Several components of the electroretinogram were studied in 31 juvenile diabetics and 15 age-matched normal controls. The diabetic group consisted of 18 patients without retinopathy and 13 with mild background retinopathy. Oscillatory potentials were measured at low-stimulation energies. Significantly reduced amplitudes and component-specific delayed peak implicit times were found in both diabetic groups compared with the data from the controls. Similar results were obtained in the photopic and scotopic electroretinogram. From these findings, we suggest that retinal dysfunction is already present in juvenile diabetics without photographic evidence of retinopathy after a mean duration of diabetes of 7 years.