In current article, results of the determination of the concentrations of vascular endothelial growth factor (VEGF), and some interleukins (IL-4, IL-6, IL-10, IL-17А) in the vitreous of patients with proliferative diabetic retinopathy are presented. We have found that in the mechanism of development of diabetic retinopathy, significant role plays an activation of local inflammation process and vascular proliferation. This is evidenced by a significant increase in the vitreous concentration of IL-4, IL-6, IL-10, IL-17A and vascular endothelial growth factor. Identified correlations between VEGF and IL-17A, between VEGF and IL-4, and between IL-17A and IL-4 show the relationship of inflammation and proliferation processes in the pathogenesis of diabetic retinopathy.