We studied the eyes of a 51-year-old man with the clinical diagnosis of fundus flavimaculatus without macular involvement by light and electron microscopy. Scanning and transmission electron microscopy revealed elevated aggregates of enlarged retinal pigment epithelial cells with apices distended by accumulated lipid membranes with a tubulo-vesicular appearance. Histochemical and ultrastructural studies failed to demonstrate abnormal accumulation of lipofuscin or acid mucopolysaccharide. The disorder, known clinically as fundus flavimaculatus, may represent two or more metabolic disorders of the retinal pigment epithelium characterized by distinct histochemical and ultrastructural features.