Hyperglycemia can result in key biochemical reactions that may contribute to thickening of basement membranes, dysfunction of pericytes and endothelial cells, and closure of retinal vessels. The Diabetes Control and Complications Trial has proved the value of good glycemic control in preventing retinopathy and/or delaying its progression. The primary care physician has a crucial role in translating these results into practice. Recognition and management of other risk factors, such as proteinuria, smoking, and hypertension, are easily done in the primary care setting. Also, appropriate referral to an ophthalmologist for retinal evaluation and treatment is both necessary and cost effective in reducing the burden of this devastating complication of diabetes.