UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549
                                    FORM 8-K

                     PURSUANT TO SECTION 13 OR 15(d) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

                         Date of Report: August 13, 2004

                                ACNB CORPORATION
--------------------------------------------------------------------------------

            (Exact name of registrant's as specified in its charter)



     PENNSYLVANIA                      0-11783                   23-2233457
--------------------------------------------------------------------------------
(State or other jurisdiction     (Commission File #)         (I.R.S. Employer
  of incorporation)                                          Identification No.)


16 LINCOLN SQUARE, GETTYSBURG, PA                                   17325
--------------------------------------------------------------------------------
(Address of principal executive offices)                         (Zip Code)

                                 (717) 334-3161
--------------------------------------------------------------------------------
              (Registrant's telephone number, including area code)


Item 9.  Regulation FD Disclosure

         On August 11, 2004, ACNB Corporation, holding company for Adams County
National Bank, issued a press release announcing its financial results for the
second quarter ended June 30, 2004. A copy of the press release is attached
hereto as Exhibit 99.1.


Item 12.  Results of Operations and Financial Condition

         Pursuant to interim guidance issued by the Securities and Exchange
Commission relating to Item 12 filing requirements, the Corporation has
furnished the information required by Item 12 under Item 9 herein.



<PAGE>



                                   SIGNATURES

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

                                                     ACNB Corporation



                                                     By: /s/ Thomas A. Ritter
                                                         -----------------------
                                                         Thomas A. Ritter
                                                         President/CEO


Dated:  August 13, 2004


<PAGE>



                                  EXHIBIT INDEX

Exhibit Number    Description


99.1              Earnings Press Release for the quarter ended June 30, 2004
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{"company-data": {"conformed-name": "ACNB CORP", "cik": "0000715579", "assigned-sic": "6022", "irs-number": "232233457", "state-of-incorporation": "PA", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "000-11783", "film-number": "04972895"}, "business-address": {"street1": "675 OLD HARRISBURG RD", "street2": "P O BOX 3129", "city": "GETTYSBURG", "state": "PA", "zip": "17325", "phone": "7173343161"}, "mail-address": {"street1": "P O BOX 3129", "street2": "675 OLD HARRISBURG RD", "city": "GETTYSBURG", "state": "PA", "zip": "17325"}}
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549
                                    FORM 8-K

                     PURSUANT TO SECTION 13 OR 15(d) OF THE
                         SECURITIES EXCHANGE ACT OF 1934

                         Date of Report: August 13, 2004

                                ACNB CORPORATION
--------------------------------------------------------------------------------

            (Exact name of registrant's as specified in its charter)

     PENNSYLVANIA                      0-11783                   23-2233457
--------------------------------------------------------------------------------
(State or other jurisdiction     (Commission File #)         (I.R.S. Employer
  of incorporation)                                          Identification No.)

16 LINCOLN SQUARE, GETTYSBURG, PA                                   17325
--------------------------------------------------------------------------------
(Address of principal executive offices)                         (Zip Code)

                                 (717) 334-3161
--------------------------------------------------------------------------------
              (Registrant's telephone number, including area code)

Item 9.  Regulation FD Disclosure

         On August 11, 2004, ACNB Corporation, holding company for Adams County
National Bank, issued a press release announcing its financial results for the
second quarter ended June 30, 2004. A copy of the press release is attached
hereto as Exhibit 99.1.

Item 12.  Results of Operations and Financial Condition

         Pursuant to interim guidance issued by the Securities and Exchange
Commission relating to Item 12 filing requirements, the Corporation has
furnished the information required by Item 12 under Item 9 herein.
SIGNATURES

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

                                                     ACNB Corporation

                                                     By: /s/ Thomas A. Ritter
                                                         -----------------------
                                                         Thomas A. Ritter
                                                         President/CEO

Dated:  August 13, 2004
EXHIBIT INDEX

Exhibit Number    Description

99.1              Earnings Press Release for the quarter ended June 30, 2004