The distribution of risk factors for cardiovascular disease in patients aged 35-44 years who were treated for human immunodeficiency virus type 1 (HIV-1) infection was compared with that for a population-based cohort. HIV-1-infected men treated with a protease inhibitor-containing regimen (n=223), compared with HIV-1-uninfected men (n=527), were characterized by a lower prevalence of hypertension, a lower mean high-density lipoprotein cholesterol level, a higher prevalence of smoking, a higher mean waist-to-hip ratio, and a higher mean triglyceride level. No difference was found for total plasma or low-density cholesterol levels, nor for the prevalence of diabetes. Similar trends were observed among female subjects. The predicted risk of coronary heart disease was greater among HIV-1-infected men (relative risk [RR], 1.20) and women (RR, 1.59; P<10(-6) for both), compared with the HIV-1-uninfected cohort. The estimated attributable risks due to smoking were 65% and 29% for HIV-1-infected men and women, respectively. Because most HIV-1-infected people will ultimately need antiretroviral therapy, risk factors for cardiovascular disease should be determined at the initiation of treatment, and interventions should be considered for all patients who have them.