================================================================================




                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                   -----------


                                    FORM 8-K


                                 CURRENT REPORT


                     Pursuant to Section 13 or 15(d) of the
                         Securities Exchange Act of 1934


                        Date of Report: September 1, 2000
                        (Date of earliest event reported)



                         CARDINAL FINANCIAL CORPORATION
             (Exact Name of Registrant as Specified in its Charter)



          Virginia                       0-24557                  54-1874630
(State or Other Jurisdiction     (Commission File Number)       (IRS Employer
      of Incorporation)                                      Identification No.)

          10555 Main Street, Suite 500
               Fairfax, Virginia                            22030
    (Address of Principal Executive Offices)             (Zip Code)


               Registrant's telephone number, including area code:
                                 (703) 934-9200




================================================================================


<PAGE>

Item 2.      Acquisition or Disposition of Assets.

         On September 1, 2000, Heritage Bancorp, Inc.  ("Heritage"),  a Virginia
corporation,  was merged with and into Cardinal Merger Corp. ("CMC"), a Virginia
corporation and wholly owned subsidiary of Cardinal  Financial  Corporation (the
"Company"),  a Virginia  corporation (the "Merger").  The Merger was consummated
pursuant to an Amended and Restated Agreement and Plan of Reorganization,  dated
as of June 19, 2000, by and between Heritage, CMC and the Company, as amended by
a First Amendment to Amended and Restated  Agreement and Plan of Reorganization,
dated as of August 28, 2000, by and between such parties,  and a related Plan of
Merger.

         Under the terms of the Merger,  each  outstanding  share of  Heritage's
common stock,  without par value ("Heritage  Common Stock"),  was converted into
the right to receive,  at the election of the  shareholder,  $6.00 in cash,  1.2
shares of the Company's 7.25% Cumulative  Convertible Preferred Stock, Series A,
par value $1.00 per share (the  "Series A Preferred  Stock"),  or a  combination
thereof,  and cash in lieu of fractional shares.  Each such election was subject
to certain  adjustments to permit the Company to issue in the aggregate an equal
amount of cash and Series A  Preferred  Stock.  There were  2,352,729  shares of
Heritage Common Stock  outstanding  immediately prior to the consummation of the
Merger.

         In connection with the Merger, The Heritage Bank, the former subsidiary
of Heritage,  became a wholly owned subsidiary of CMC. In addition, three of the
former directors of Heritage became directors of the Company.

         For a more  detailed  description  of the  Merger,  see the Joint Proxy
Statement/Prospectus  that  is a part of  Amendment  No.  1 to the  Registration
Statement on Form S-4, Registration No. 333-38380, filed by the Company with the
Securities and Exchange Commission on June 20, 2000, under the Securities Act of
1933, as amended, which is incorporated herein by reference.


Item 7.      Financial Statements, Pro Forma Financial Information and Exhibits.

      (a)    Financial Statements of Businesses Acquired.

             The  financial  statements  of Heritage  required to be included in
             this report are not  included  herein  pursuant to Item 7(a)(4) and
             will be filed as soon as possible.

      (b)    Pro Forma Financial Information.

             The pro forma financial information required to be included in this
             report are not included herein pursuant to Item 7(b)(2) and will be
             filed as soon as possible.




                                      -2-
<PAGE>

       (c)    Exhibits.

              Exhibit No.           Description
              -----------           -----------

                 2.1         Amended  and   Restated   Agreement   and  Plan  of
                             Reorganization,  dated as of June 19, 2000,  by and
                             between  Heritage,  CMC and the  Company,  filed as
                             Exhibit 2.1 to Amendment No. 1 to the  Registration
                             Statement on Form S-4 (File No.  333-38380),  dated
                             June 20, 2000, incorporated herein by reference.

                 2.2         First  Amendment to Amended and Restated  Agreement
                             and Plan of Reorganization,  dated as of August 28,
                             2000,  by  and  between   Heritage,   CMC  and  the
                             Company.*



-------------------
* Filed herewith.

















                                      -3-
<PAGE>

                                    SIGNATURE

         Pursuant to the requirements of the Securities Exchange Act of 1934, as
amended,  the  registrant has duly caused this report to be signed on its behalf
by the undersigned hereunto duly authorized.


                                         CARDINAL FINANCIAL CORPORATION



Dated: September 18, 2000                By: /s/ Joseph L. Borrelli
                                             -----------------------------------
                                             Joseph L. Borrelli
                                             Chief Financial Officer





<PAGE>

                                INDEX TO EXHIBITS


No.                  Description
---                  -----------

2.1           Amended and Restated Agreement and Plan of  Reorganization,  dated
              as of June  19,  2000,  by and  between  Heritage  Bancorp,  Inc.,
              Cardinal Merger  Corporation and Cardinal  Financial  Corporation,
              filed  as  Exhibit  2.1 to  Amendment  No.  1 to the  Registration
              Statement on Form S-4 (File No.  333-38380),  dated June 20, 2000,
              incorporated herein by reference.

2.2           First  Amendment  to Amended and  Restated  Agreement  and Plan of
              Reorganization,  dated  as of  August  28,  2000,  by and  between
              Heritage Bancorp,  Inc.,  Cardinal Merger Corporation and Cardinal
              Financial Corporation.*



-------------------
* Filed herewith.
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{"company-data": {"conformed-name": "CARDINAL FINANCIAL CORP", "cik": "0001060523", "assigned-sic": "6021", "irs-number": "541874630", "state-of-incorporation": "VA", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "000-24557", "film-number": "724632"}, "business-address": {"street1": "10641 LEE HIGHWAY", "city": "FAIRFAX", "state": "VA", "zip": "22030", "phone": "7039349200"}, "mail-address": {"street1": "10641 LEE HIGHWAY", "city": "FAIRFAX", "state": "VA", "zip": "22030"}}
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                   -----------

                                    FORM 8-K

                                 CURRENT REPORT

                     Pursuant to Section 13 or 15(d) of the
                         Securities Exchange Act of 1934

                        Date of Report: September 1, 2000
                        (Date of earliest event reported)

                         CARDINAL FINANCIAL CORPORATION
             (Exact Name of Registrant as Specified in its Charter)

          Virginia                       0-24557                  54-1874630
(State or Other Jurisdiction     (Commission File Number)       (IRS Employer
      of Incorporation)                                      Identification No.)

          10555 Main Street, Suite 500
               Fairfax, Virginia                            22030
    (Address of Principal Executive Offices)             (Zip Code)

               Registrant's telephone number, including area code:
                                 (703) 934-9200

================================================================================
Item 2.      Acquisition or Disposition of Assets.

         On September 1, 2000, Heritage Bancorp, Inc.  ("Heritage"),  a Virginia
corporation,  was merged with and into Cardinal Merger Corp. ("CMC"), a Virginia
corporation and wholly owned subsidiary of Cardinal  Financial  Corporation (the
"Company"),  a Virginia  corporation (the "Merger").  The Merger was consummated
pursuant to an Amended and Restated Agreement and Plan of Reorganization,  dated
as of June 19, 2000, by and between Heritage, CMC and the Company, as amended by
a First Amendment to Amended and Restated  Agreement and Plan of Reorganization,
dated as of August 28, 2000, by and between such parties,  and a related Plan of
Merger.

         Under the terms of the Merger,  each  outstanding  share of  Heritage's
common stock,  without par value ("Heritage  Common Stock"),  was converted into
the right to receive,  at the election of the  shareholder,  $6.00 in cash,  1.2
shares of the Company's 7.25% Cumulative  Convertible Preferred Stock, Series A,
par value $1.00 per share (the  "Series A Preferred  Stock"),  or a  combination
thereof,  and cash in lieu of fractional shares.  Each such election was subject
to certain  adjustments to permit the Company to issue in the aggregate an equal
amount of cash and Series A  Preferred  Stock.  There were  2,352,729  shares of
Heritage Common Stock  outstanding  immediately prior to the consummation of the
Merger.

         In connection with the Merger, The Heritage Bank, the former subsidiary
of Heritage,  became a wholly owned subsidiary of CMC. In addition, three of the
former directors of Heritage became directors of the Company.

         For a more  detailed  description  of the  Merger,  see the Joint Proxy
Statement/Prospectus  that  is a part of  Amendment  No.  1 to the  Registration
Statement on Form S-4, Registration No. 333-38380, filed by the Company with the
Securities and Exchange Commission on June 20, 2000, under the Securities Act of
1933, as amended, which is incorporated herein by reference.

Item 7.      Financial Statements, Pro Forma Financial Information and Exhibits.

      (a)    Financial Statements of Businesses Acquired.

             The  financial  statements  of Heritage  required to be included in
             this report are not  included  herein  pursuant to Item 7(a)(4) and
             will be filed as soon as possible.

      (b)    Pro Forma Financial Information.

             The pro forma financial information required to be included in this
             report are not included herein pursuant to Item 7(b)(2) and will be
             filed as soon as possible.

                                      -2-
(c)    Exhibits.

              Exhibit No.           Description
              -----------           -----------

                 2.1         Amended  and   Restated   Agreement   and  Plan  of
                             Reorganization,  dated as of June 19, 2000,  by and
                             between  Heritage,  CMC and the  Company,  filed as
                             Exhibit 2.1 to Amendment No. 1 to the  Registration
                             Statement on Form S-4 (File No.  333-38380),  dated
                             June 20, 2000, incorporated herein by reference.

                 2.2         First  Amendment to Amended and Restated  Agreement
                             and Plan of Reorganization,  dated as of August 28,
                             2000,  by  and  between   Heritage,   CMC  and  the
                             Company.*

-------------------
* Filed herewith.

                                      -3-
SIGNATURE

         Pursuant to the requirements of the Securities Exchange Act of 1934, as
amended,  the  registrant has duly caused this report to be signed on its behalf
by the undersigned hereunto duly authorized.

                                         CARDINAL FINANCIAL CORPORATION

Dated: September 18, 2000                By: /s/ Joseph L. Borrelli
                                             -----------------------------------
                                             Joseph L. Borrelli
                                             Chief Financial Officer
INDEX TO EXHIBITS

No.                  Description
---                  -----------

2.1           Amended and Restated Agreement and Plan of  Reorganization,  dated
              as of June  19,  2000,  by and  between  Heritage  Bancorp,  Inc.,
              Cardinal Merger  Corporation and Cardinal  Financial  Corporation,
              filed  as  Exhibit  2.1 to  Amendment  No.  1 to the  Registration
              Statement on Form S-4 (File No.  333-38380),  dated June 20, 2000,
              incorporated herein by reference.

2.2           First  Amendment  to Amended and  Restated  Agreement  and Plan of
              Reorganization,  dated  as of  August  28,  2000,  by and  between
              Heritage Bancorp,  Inc.,  Cardinal Merger Corporation and Cardinal
              Financial Corporation.*

-------------------
* Filed herewith.