The aim of this study was to assess the prevalence of long-term complications in a large sample of French NIDDM patients. Therefore, 427 NIDDM patients 35-74 years old were recruited in ten centers. Standardized clinical criteria and central reading for retinal and electrocardiographic changes were used to assess the presence of complications. The prevalence rates of complications were 29.7% and 3.3% for background and proliferative retinopathy; 21.8%, 6.1%, and 2.8% for microalbuminuria, proteinuria, and renal insufficiency; 19.9 and 11.7% for asymptomatic and symptomatic pheripheral neuropathy; 8.2% for orthostatic hypotension; 10.1% and 8.4% for angina pectoris and myocardial infarction; and 13.1% and 6.3% for mild and moderate to severe peripheral vascular disease, respectively. In conclusion, prevalence rates in this study were lower than in most studies from other countries.