1 Page 14 Exhibit 11 NATIONAL SERVICE INDUSTRIES, INC. AND SUBSIDIARIES COMPUTATIONS OF NET INCOME PER SHARE OF COMMON STOCK (In thousands, except per-share data) THREE MONTHS ENDED NOVEMBER 30 1994 1993 Primary: Weighted Average Number of Shares (determined on a monthly basis) 49,244 49,562 Net Income $21,114 $19,172 Primary Earnings per Share $ .43 $ .39 Fully Diluted: Weighted Average Number of Shares Outstanding 49,244 49,562 Additional Shares Assuming Exercise of Options: Options exercised 978 746 Treasury stock purchased with proceeds (902) (689) Average Common Shares Outstanding (as adjusted) 49,320 49,619 Net Income $21,114 $19,172 Fully Diluted Earnings per Share $ .43 $ .39