Eighty-six eyes of 46 patients were studied retrospectively to determine the incidence of posterior synechiae after laser iridectomy. All eyes were dilated and studied with a slit lamp. The incidence of permanent posterior synechiae in the eyes in this study (37%) is much higher than that previously reported. There was a strong positive correlation between the use of miotic agents postoperatively and the finding of posterior synechiae. The probable pathogenesis of this complication is discussed, and methods to decrease the incidence of this complication are given.