OBJECTIVE: Determine the prevalence of erectile dysfunction in patients undergoing hemodialysis MATERIALS AND METHODS: This cross-sectional study was carried out to determine the prevalence of erectile dysfunction in a population of 58 patients in hemodialysis program. Erectile dysfunction was assessed by using the International Index of Erectile Function (IIEF). Information on demographic data, renal failure, comorbidities, laboratory tests and search for medical treatment for erectile dysfunction by means of interviews and researches in medical charts was obtained. Student t test was utilized to compare the laboratory results between group of patients with and without erectile dysfunction. The chi-square test was utilized to compare the comorbidities and the characteristics of the population studied between the groups of patients with and without erectile dysfunction. The significance level considered was 5% RESULTS: Mean patient age was 50.2 ± 14.6 years and the time of hemodialysis was 30.4 ± 28.4 months. The prevalence of erectile dysfunction was 60.3%. A progressive increase respecting the age was reported. In patients younger than 50 years, this prevalence reached 31.4% and in patients older than 50 years, this prevalence reached 68.6%. With respect to the comorbidities, hypertensive patients prevailed with 94.8% of the total, whilst diabetic patients represented 24.9%. However only the association between diabetes and erectile dysfunction was significant. Patients with erectile dysfunction presented significantly lower values for serum creatinine and Kt/V. There was no variation between the groups with reference to calcium, potassium, phosphorus, hematocrit, hemoglobin, pre- and post-dialysis urea values. There was no correlation between erectile dysfunction and time of dialysis. Amongst patients with erectile dysfunction, 8.6% sought medical care CONCLUSIONS: The prevalence of erectile dysfunction in patients in hemodialysis program was of 60.3%. Age, diabetes and hemodialysis characteristics are associated to higher incidence of erectile dysfunction.