Epiretinal membranes at the macula were seen in 4% of the eyes of 355 patients with homozygous sickle cell (SS) disease and sickle cell haemoglobin-C (SC) disease under the age of 60 years. The presence of proliferative sickle retinopathy (PSR), the extent of involvement of PSR, and vitreous haemorrhage all constitute risk factors for the formation of epiretinal membranes. The occlusion of PSR lesions by treatment appears to reduce the risk of epiretinal membranes being formed.