We studied 41 young and middle-aged adults who developed innumerable, small, round, uniformly sized, yellow, subretinal nodules that were often arranged in clusters throughout the posterior fundus. Angiographically, they fluoresced discretely during the early arteriovenous phase. In middle or later life 17 of these patients developed visual loss caused by vitelliform retinal detachment in the macula of one or both eyes. Spontaneous resolution of the detachment and retention of good visual acuity occurred frequently. We found evidence indicating that the multiple, small, subretinal nodules are probably focal areas of pigment epithelial attenuation overlying nodular thickenings of the basement membrane of the pigment epithelium. The term basal laminar drusen would distinguish these nodules from those of typical drusen, which are caused by focal detachments of attenuated pigment epithelium and its usually normal-thickness basement membrane from the inner collagenous zone of Bruch's membrane.