EXHIBIT 11 FIRST KEYSTONE CORPORATION COMPUTATION OF EARNINGS PER COMMON SHARE For the Nine Month Period Ended September 30, 2003 and 2002 (Dollars in Thousands) 2003 2002 <s> <c> <c> Primary Net Income $ 5,469 $ 4,939 Shares Weighted average number of common shares outstanding 2,951,391 2,974,288 Adjustments - increases or decreases None None Weighted average number of common shares outstanding as adjusted 2,951,391 2,974,288 Primary earnings per common share $ 1.85 $ 1.66 Assuming full dilution Net Income $ 5,469 $ 4,939 Shares Weighted average number of common shares outstanding 2,951,391 2,974,288 Adjustments - increases or decreases 7,436 3,242 Weighted average number of common shares outstanding as adjusted 2,958,827 2,977,530 Earnings per common share assuming full dilution $ 1.85 $ 1.66 26