OBJECTIVE To identify factors associated with a high risk of diabetic retinopathy in order to rank patients for urgency of examination by fundal photography. METHODS Retrospective case survey. METHODS Eight hundred and eighty-eight consecutive diabetic patients who were routinely referred for mydriatic fundal photography to the Queen Elizabeth Hospital, Adelaide, between August 1987 and May 1992. METHODS The prevalence of non-proliferative and proliferative diabetic retinopathy and patient biochemical and demographic characteristics and urinary albumin excretion rate. RESULTS The prevalences of nonproliferative and proliferative diabetic retinopathy were 18.1% and 2.4%, respectively. Multiple logistic regression analysis established that treatment with insulin or oral hypoglycaemic drugs was associated with the highest risk of diabetic retinopathy (odds ratio [OR], 14.7; 95% confidence interval [CI], 3.4-63.2), while duration of diabetes > or = 7 years (OR, 3.6; CI, 1.9-6.8), age 50-66 years (OR, 2.1; 95% CI, 1.1-4.0) and albumin excretion rate > or = 21 micrograms/min (OR, 2.2; 95% CI, 1.1-4.5) were also significant risk factors. Non-significant variables were hypertension, obesity and sex. CONCLUSIONS Diabetic patients may be ranked for urgency of retinal photographic screening based on mode of treatment and duration of diabetes, thereby facilitating examination of patients at highest risk of asymptomatic diabetic retinopathy and increasing the efficiency of the screening program.