We report the clinical and electrophysiologic findings in three patients with Bietti's crystalline corneal-retinal dystrophy. The initial evaluation in one patient demonstrated diffuse disease involving retinal pigment epithelium and choriocapillaris with severe widespread disturbance of retinal function. The patient's disease progressed greatly from the age of 36 to 47 years. Two brothers had regional involvement of the posterior pole with disturbances of retinal function attributable to localized disease, and there was only mild progression in these patients. A corneal biopsy specimen from the more severely affected patient and biopsy specimens from a patient whose case had been previously reported demonstrated crystals resembling cholesterol or cholesterol ester and complex lipid inclusions in corneal and conjunctival fibroblasts. Similar inclusions were present in circulating lymphocytes, suggesting that Bietti's crystalline corneal-retinal dystrophy may be due to a systemic abnormality of lipid metabolism.