As the world has entered the fourth decade of the AIDS epidemic, Men who have sex with men (MSM) continue to be disproportionately affected by HIV and victims of stigma, prejudice, and discrimination in the Caribbean and Haiti. Using a mixed-methods realist design, we have engaged with MSM communities, healthcare providers, policymakers, and members of civil society to analyze the impact of stigma on the linkages across the continuum of HIV services through engagement, linkage, and retention. Findings showed that from the social construction of heteronormativity to Christian religious and political influences, several factors lie behind sexual and HIV-related stigma, resulting in loss to follow-up and failure to realize the health benefits of proper treatment fully. However, societal engagement and partnerships, multi-level and contextual-based interventions can produce stigma mitigation through personal, health systems’ and contextual mechanisms for better engagement, adherence, and retention in healthcare.