Erectile dysfunction (ED) is one of late complication of diabetes mellitus. The aim of the study, performed in the Department of Gastroenterology and Metabolic Diseases and in Diabetic Clinics, was to assess the prevalence of the ED and relationship to other late complications of diabetes. 6670 diabetic men was included (39 did not agree to participate) to the study. The mean age of patients was 55.14 ± 12.11 yrs, mean ± SD (from 18 to 91 yrs) ED was found in 4,637 (69.52%). In subgroup with type 1 diabetes (1,072 men) ED occured in 591 (55.13%). In patients with type 2 diabetes (5,538 men) ED was reported in 4,009 men (72.39%). The onset of ED occurred on average after 3.11 ± 6.28 yrs (–33.42) since time of diagnosis of the diabetes in all group, but in patients with IDDM after 9.10 ± 7,81 yrs (–15.42), and in patients with NIDDM 2.48 ± 5.55 yrs (–30.30). The duration of ED has positive correlation with age (r = 0.4552; P < 0.01), duration of diabetes (r = 0.0746; P < 0.01), time length of coronary heart disease (r = 0.4547; P < 0.01), brain vascular disease (r = 0.2881; P < 0.01), legs vascular disease (r = 0.3585; P < 0.01) retinopathy (r = 0.3482; P < 0.01) nephropathy (r = 0.2087; P < 0.10), neuropathy (r = 0.407; P < 0.01). The ED was poorly recognized in Diabetic Clinics, only 2,137 (33%) patients addressed this problem to their physicians. ED is frequent complication of diabetes among other is vascular sometimes neglected in diabetic care.