In type I diabetic patients association has been found between the insertion/deletion (I/D) polymorphism in the gene of angiotensin converting enzyme and the presence of diabetic nephropathy. The aim of that study was to assess this association in a cohort of type II diabetics. We examined 109 patients of more than 10 years duration of type II diabetes. Nephropathy (defined as at least confirmed albuminuria > 30 mg/24h) was present in 37 subjects. The I/D polymorphism was analyzed with PCR technique. Allele frequencies in the overall diabetic population did not differ significantly from the normal population. Distribution of genotypes was not significantly different between examined patients with and those without nephropathy. We conclude that the distribution of ACE gene polymorphism is similar in diabetic subjects and in general population and there is not association between I/D polymorphism and nephropathy in type II diabetic patients.