A 19-year-old Japanese woman developed diabetes mellitus, diabetes insipidus and optic atrophy. Other abnormal ocular findings included color blindness, elevated dark adaptation threshold, loss of oscillatory potentials after a single white flash electroretinogram (ERG), reduced cone response in photopic ERG, and reduced pupillary response to light and convergence. Diabetic retinopathy, which has been thought to be very rare in this syndrome, also was found in the fundi of this patient.