We obtained electroretinograms (ERGs) from normal subjects and from patients with sickle cell disease. The ERG components (a-wave, b-wave, and oscillatory potentials) obtained from normal subjects and patients without peripheral retinal neovascularization did not differ in either amplitude or implicit time. However, ERG components obtained from patients with peripheral retinal neovascularization were reduced in amplitude compared with those obtained from normal subjects or patients without neovascularization. The reduced a-wave, b-wave, and oscillatory potential amplitudes may have been due to photoreceptor dysfunction secondary to choroidal ischemia or possibly increased oxygen demands by the inner retina. Ischemia of the inner retina may also have contributed to the altered b-wave and oscillatory potentials. These results suggest that ERG provides a means of assessing the consequence of peripheral retinal ischemia to retinal cell function and could be of value in monitoring patients with sickle cell disease for the development of clinically significant peripheral retinal neovascularization.