The renin-angiotensin system is a major regulator of blood pressure. Angiotensin-converting enzyme ( ACE ) polymorphism may play a role in stroke susceptibility, but the results of association studies in different populations of the world were inconsistent. The aim of this study was to investigate the association of I/D polymorphism of the ACE gene with the risk of cerebral stroke (CS) in hypertensive patients from Central Russia. We studied DNA samples obtained from 901 subjects, including 470 CS patients and 431 sexand age-matched healthy controls. The I/D polymorphism of the ACE gene was genotyped by PCR. The comparative analysis showed no difference in allele and genotype frequencies of the ACE polymorphism between the cases and control groups. The analysis stratified by gender did not reveal the associations of the ACE gene I/D polymorphism with the CS risk. The study showed that I/D polymorphism of the ACE gene is not a susceptibility gene of cerebral stroke in Central Russia population.