We determined serum levels of vascular endothelial growth factor (VEGF) at different stages of diabetic retinopathy before laser photocoagulation in 65 patients (31 nonproliferative (Group 1) and 34 proliferative (Group 2)) and in healthy controls (Group 3). VEGF levels in all groups were different. There was a significant correlation between VEGF concentration and HbA1c levels. VEGF may be involved in the prediction of diabetic retinopathy and contributes to endothelial damage in diabetics.