objective: to study the prevalence of microalbuminuria and its association with more severe diabetic retinopathy in a group of insulin-dependent diabetic patients. materials and methods: during the period of january 1998 to december 2005 we examined 360 insulin-dependent diabetic patients with at least five years of evolution. we evaluated the presence of microalbuminuria by immunoanalysis. patients were evaluated by direct and indirect ophthalmoscopy and classified as non-retinopathy, non-proliferative, severe non-proliferative/proliferative, or macular edema. results: in this study, 24.1% of patients had microalbuminuria. most of the patients with microalbuminuria and macroalbuminuria were male and had a longer history of diabetes. microalbuminuria was associated with more severe diabetic retinopathy. conclusions: all patients with insulin-dependent diabetes of at least five years？ evolution should undergo an evaluation of renal function including tests for microalbuminuria. in the presence of microalbuminuria an ophthalmologic follow-up may be particularly important.