Idiopathic central serous chorioretinopathy (ICSC) is typically described as a self-limited, unilateral disease that affects healthy, young adult males. The authors studied 13 patients (14 eyes) who had documented spontaneous resolution of symptomatic macular detachments. These patients were evaluated in a longitudinal fashion to determine the fate of the retinal pigment epithelium (RPE) as viewed angiographically, both in the initially affected eyes and the fellow eyes. At the time of follow-up examination of the initially affected eyes, nonleaking RPE defects had developed inside the areas of previous serous detachment in all cases. Nonleaking RPE defects had developed outside these areas in six (43%) eyes. Two (14%) eyes had new, asymptomatic macular detachments. Six (42%) fellow eyes had new RPE window defects; two (17%) of them also had active RPE dye leakage resulting in asymptomatic macular detachment at the final examination. Four (29%) originally involved eyes and one (8%) fellow eye lost more than two lines of Snellen visual acuity during the follow-up period. The authors' results suggest that ICSC may be a progressive bilateral disease that develops asymmetrically and causes diffuse RPE changes not localized to the area of serous detachment. Long-term follow-up of these patients may, therefore, be advisable.