EXHIBIT 11 MERIDIAN DIAGNOSTICS, INC. AND SUBSIDIARIES Computation of Earnings Per Common Share Period Ended December 31, 1997 Weighted Avg. Earnings Number of Per Common Shares Net Common Outstanding Income Share Use ------------- --------- -------- ---- QUARTER ENDED DECEMBER 31, 1997: Shares outstanding October 1, 1997 14,365,289 $ - $ - $ - Weighted average shares issued during the period (6,643 shares) 4,106 - - - Net Income - 971,580 - - ---------- -------- ------- Basic earnings per common share 14,369,395 $971,580 $ .068 $ .07 Effect of outstanding stock options (618,948 shares) 342,510 - - ---------- -------- ------- Diluted earnings per common share 14,711,905 $971,580 $ .066 $ .07 ========== ======== ======