Haiti has the highest number of individuals living with HIV in the Caribbean. Due to Haiti’s resource-poor environment and inadequate mental health and substance abuse services, adherence to antiretroviral therapy (ART) may be especially difficult. This study examined associations among demographics, maladaptive coping, partner conflict, alcohol problems, depression, and negative attitudes about medications and their impact on adherence among 194 HIV-positive Haitians. In a mediated directional structural equation model, depression and negative attitudes about ART directly predicted poorer adherence. Greater partner conflict, maladaptive coping and alcohol problems predicted more depression. Maladaptive coping predicted a negative attitude about ART. Alcohol problems predicted partner conflict and maladaptive coping. Significant indirect effects on adherence mediated through both depression and negative attitudes about ART include negative effects of female gender, alcohol problems and maladaptive coping. Results highlight the importance of integrated care for depression, alcohol use and other psychosocial problems to increase ART adherence.