Accelerated atherosclerosis is a major complication of long-term diabetes mellitus, and this is partly due to associated abnormalities of lipoprotein metabolism. Hypertriglyceridemia is usually due to poorly controlled diabetes and responds to improved glucose control. Hypercholesterolemia is usually not related to poor diabetic control and should be treated with a cholesterol lowering diet and drugs according to the National Cholesterol Education Program guidelines. Low HDL-C is common in NIDDM and does not fully return to normal with improved diabetic control. Dyslipidemia in diabetics should be aggressively identified and treated to decrease cardiovascular risk.