The global burden of diabetes mellitus is growing at such an alarming rate that the growth beats the periodic estimates and future projections by a wide margin with consistency. Diabetic retinopathy (DR), the most common microvascular complication of diabetes, is likely to be present in about a third of diabetic subjects at any given time, and eventually affects nearly all diabetics after two to three decades. This exponential increase in systemic diabetes and concurrent retinopathy has projected DR as one of the leading causes of visual loss globally. This chapter covers the pathogenesis, clinical features of diabetic retinopathy, natural course and grading of diabetic retinopathy, differential diagnosis of diabetic retinopathy, imaging in diabetic retinopathy, screening for diabetic retinopathy, medical management of diabetic retinopathy, and vitrectomy.