Causes for loss-to-follow-up, including early refusals of and stopping antiretroviral therapy (ART), in Malawi's Option B+ program are poorly understood. This study examines the main barriers and facilitators to uptake and adherence to ART under Option B+. In depth interviews were conducted with HIV-infected women who were pregnant or postpartum in Lilongwe, Malawi (N = 65). Study participants included women who refused ART initiation (N = 10), initiated ART and then stopped (N = 26), and those who initiated ART and remained on treatment (N = 29). The barriers to ART initiation were varied and included concerns about partner support, feeling healthy, and needing time to think. The main reasons for stopping ART included side effects and lack of partner support. A substantial number of women started ART after initially refusing or stopping ART. There were several facilitators for re-starting ART, including encouragement from community health workers, side effects subsiding, decline in health, change in partner, and fear of future sickness. Amongst those who remained on ART, desire to prevent transmission and improve health were the most influential facilitators. Reasons for refusing and stopping ART were varied. ART-related side effects and feeling healthy were common barriers to ART initiation and adherence. Providing consistent pre-ART counseling, early support for patients experiencing side effects, and targeted efforts to bring women who stop treatment back into care may improve long term health outcomes.