Exhibit 11.1(a) Renal Treatment Centers, Inc. and Subsidiaries COMPUTATION OF PRIMARY EARNINGS PER SHARE for the quarter ended March 31, 1997 and 1996 Three Months Ended March 31, 1997 1996 - ----------------------------------------------------------------------------------------------------- Net income $ 6,019,397 $ 3,372,288 - ----------------------------------------------------------------------------------------------------- Weighted average number of shares outstanding 24,509,763 24,036,542 Weighted average number of maximum shares subject to exercise under outstanding stock options 1,721,920 1,349,743 - ----------------------------------------------------------------------------------------------------- 26,231,683 25,386,285 Less treasury shares assumed purchased with proceeds from assumed exercise of outstanding common stock options 970,496 625,473 - ----------------------------------------------------------------------------------------------------- Weighted average number of common and common stock equivalents outstanding 25,261,187 24,760,812 ===================================================================================================== Net income per common and common stock equivalent $ 0.24 $ 0.14 =====================================================================================================