Studying 445 diabetic patients, we investigated the effects of sex, age, duration of disease, and mode of diabetes therapy on the prevalence of diabetic retinopathy. Of the study participants, 193 were treated with insulin injections, 164 took oral antidiabetic medications, and 88 were managed on diet alone. The prevalence of diabetic retinopathy was highest among insulin-treated patients (64%), while in the oral medication and diet groups, it was 36% and 12%, respectively. Diabetic retinopathy was more prevalent among patients with prolonged duration of disease. Sex and age did not seem to affect the prevalence of diabetic retinopathy when adjustments were made for the duration of disease.