It is currently unknown whether there is an increased risk of coronary heart disease (CHD) in patients with HIV infection. In addition, the contribution of antiretroviral therapy (ART) to CHD risk has not been quantified. We reviewed administrative claims data for HIV-infected and -uninfected individuals from the California Medicaid population and compared the incidence of and relative risk (RR) for CHD using log-linear regression analyses between groups. The association between exposure to ART and CHD incidence was also assessed. Of 3,083,209 individuals analyzed, 28,513 were HIV-infected. The incidence of CHD among young men (up to age 34) and women (up to age 44) with HIV infection was significantly higher than that among non-HIV-infected individuals. The covariate-adjusted RR for the development of CHD in individuals receiving ART compared with those not receiving ART was 2.06 (P < 0.001) in HIV-infected individuals aged 18-33 years. There were no statistically significant associations between ART exposure and CHD in other age groups. CHD incidence appears accelerated among young HIV-infected individuals. Strategies to reduce CHD risk should be incorporated into HIV primary care.