In patients treated with oral indomethacin for four weeks after intracapsular cataract extraction, five of 57 eyes (9%) had cystoid macular edema four to six weeks postoperatively as shown by fluorescein angiography. In a control group not treated with indomethacin, 15 of 34 eyes (44%) had cystoid mascular edema. Oral indomethacin, therefore, caused a statistically significant decrease in the incidence of aphakic cystoid macular edema.