This study was designed to investigate whether angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism is associated with erectile dysfunction (ED) in Russian men with metabolic syndrome (MS). A total of 331 men with MS were studied. All patients underwent complex evaluation including the International Index of Erectile Function (IIEF) questionnaire. The ACE I/D polymorphism was determined by polymerase chain reaction. Overall, 182 men (55.0%) had ED according to the IIEF erectile function domain score. In the ED group, the prevalence of DD genotype was found to be significantly higher compared to the non-ED group (P<0.001). In both groups, patients with DD genotype were significantly younger than patients with other genotypes (P<0.001). In addition, in the ED group, the disease affected patients with DD genotype at a significantly younger age (P<0.001). Obtained results give evidence to support the finding that the D allele is a risk factor for the micro- and macrovascular diseases.