The incidence of clinically significant cystoid macular edema (CME) following cataract surgery has risen sharply with the widespread utilization of intraocular lenses. To evaluate the factors contributing to the incidence of CME, the senior author has divided 1808 of his own cataract cases into three groups according to procedures used: 1) intracapsular cataract extraction (ICCE) with no lens implantation; 2) ICCE with implantation of an iris-supported lens; and 3) extracapsular cataract extraction (ECCE) with implantation of a posterior chamber lens. The incidence of CME in these three groups was 2%, 9.9%, and 1.2%, respectively. Contributing factors and visual outcome in all three groups are reviewed. It is concluded that many of the problems associated with ICCE and iris-supported lens implantation seem to be eliminated with the ECCE-posterior chamber IOL procedure. However, it is emphasized that careful longterm follow-up is required to determine safety.