Objectives : The purpose of this study is to evaluate the association of the angiotensin converting enzyme (ACE) insertion/deletion (I/D) polymorphism with cardiovascular disease risk factors. Methods : Out of a total of 608 middle-aged adults who visited local health centers, 424 subjects (104 male, 320 female) who had not been diagnosed with hypertension, diabetes mellitus, or hyperlipidemia were included in this study. ACE genotypes were determined in all subjects by polymerase chain reaction methods. Results : Statistical differences in high-density lipoprotein (HDL) cholesterol levels according to ACE genotype were observed using ANOVA (p<0.05), but no differences were found in other cardiovascular risk factors. Specifically, men with the DD and DI genotypes had significantly lower HDL cholesterol levels than those with the 11 genotype based on the LSD multi-comparison test (p<0.05). Conclusions : In men, the D-allele of the ACE I/D polymorphism was significantly associated with reduced HDL cholesterol levels. In the future, larger studies are needed to confirm this relationship between ACE I/D polymorphism and HDL cholesterol.