We explored the association between HIV-related stigma and experiences of intimate partner violence (IPV) and depression with viral load suppression, and medication and visit adherence in postpartum women receiving lifelong antiretroviral therapy (ART) (N = 200). We administered a cross-sectional survey to 200 women with HIV at 12 months postpartum who were enrolled in the MOTIVATE trial. The MOTIVATE study is a cluster-randomized trial evaluating the impact of community mentor mothers and text messaging on PMTCT outcomes in southwestern Kenya. Simple and multivariable logistic regression analysis was performed in STATA. Women who experienced stigma or IPV were more likely to miss clinic visits (internalized stigma aOR 1.30 95%CI 1.03–1.64; anticipated stigma aOR 1.20 95%CI 1.04–1.42; IPV aOR 15.71 95%CI 1.47–167.80), report difficulty taking ART drugs (internalized stigma aOR 1.32 95%CI 1.10–1.58; anticipated stigma aOR 1.14 95%CI 1.01–1.30) and not taking medication as prescribed (IPV aOR 2.00 95%CI 1.05–3.74). Depression was additionally associated with decreased odds of viral load suppression (aOR 0.16 95%CI 0.04–0.76). There is need to develop tailored psychosocial interventions within PMTCT programs that appropriately address mental health, stigma, and violence.