Risk factors for non proliferative retinopathy were investigated by comparing two groups of insulin dependent diabetic patients: group NR of 25 patients without retinopathy and group R of 25 patients studied at the time of discovery of non proliferative retinopathy. The two groups were matched for age, sex and diabete duration. They were significantly different for insulin treatment regimens, blood glucose control and blood pressure. Lipid parameters and renal function were similar in the two groups.