This study examined the relationship of adherence to antiretroviral treatment with three types of social support (partner, friends, and family) and use of two coping strategies (denial and substance use). Participants were 73 men and women with HIV infection drawn from a larger sample of 186 clinical trial patients. Based on inclusion criteria, parent trial participants taking antiretroviral therapies, and those with complete data on self-reported measures of adherence were considered eligible for the present study. Overall, 26% of participants were found to be nonadherent, which was defined as one or more missed doses of treatment in the prior 4-day period. Logistic regression analysis was conducted to determine associations of sociodemographic and psychosocial variables with adherence to antiretroviral regimen. Results indicated that heterosexual participants (p < 0.01) and participants of Latino ethnicity (p < 0.05) were significantly more likely to report missed medications. Perceived satisfaction with support from a partner was associated with taking antiretroviral therapy as prescribed, whereas satisfaction with support from friends and from family was not significantly related to adherence. Examination of coping strategies showed that participants reporting drug and alcohol use (p <.05) to cope with HIV-related stress were more likely to be nonadherent. These findings call for adherence interventions designed to address barriers and strengths, such as community norms or traditional cultural values, specific to certain populations. Furthermore, couple-based approaches enlisting partner support may help persons living with HIV to adhere to antiretroviral regimens.