We determined the prevalence of depression in HIV-infected adults on antiretroviral therapy in rural Rwanda and measured the association of depression with non-adherence. In all, 292 patients on antiretroviral therapy for ≥6 months were included. Adherence was self-reported by four-day recall, two- and seven-day treatment interruptions, and the CASE Index, which is a composite score accounting for difficulty taking medications on time, the average number of days per week a dose is missed, and the most recent missed dose. A total of 84% and 87% of participants reported good adherence by the four-day recall and CASE Index, respectively; 13% of participants reported two-day treatment interruptions; and 11% were depressed. Depression was significantly associated with two-day treatment interruptions but not with other measures of non-adherence. Self-reported adherence to antiretroviral therapy in rural Rwanda is high. Adherence assessments that do not consider treatment interruptions may miss important patterns of non-adherence, which may be especially prevalent among depressed individuals. Mental health interventions incorporated into routine HIV care may lead to improvements in mental health and adherence.