Monitoring retention of people living with HIV (PLHIV) in the HIV care and treatment cascade is essential to guide program strategy and evaluate progress toward globally-endorsed 90-90-90 targets (i.e., 90% of PLHIV diagnosed, 81% on sustained antiretroviral therapy (ART), and 73% virally suppressed). We describe national retention from diagnosis throughout the cascade for patients receiving HIV services in Haiti during 1985-2015, with a focus on those receiving HIV services during 2008-2015. Among the 266,256 newly diagnosed PLHIV during 1985-2015, 49% were linked-to-care, 30% started ART, and 18% were retained on ART by the time of database closure. Similarly, among the 192,187 newly diagnosed HIV-positive patients during 2008-2015, 50% were linked to care, 31% started ART, and 19% were retained on ART by the time of database closure. Most patients (90-92%) at all cascade steps were adults (≥ 15 years old), among whom the majority (60-61%) were female. During 2008-2015, outcomes varied significantly across 42 administrative districts (arrondissements) of residence; cumulative linkage-to-care ranged from 23% to 69%, cumulative ART initiation among care enrollees ranged from 2% to 80%, and cumulative ART retention among ART enrollees ranged from 30% to 88%. Compared with adults, children had lower cumulative incidence of ART initiation among care enrollees (64% versus 47%) and lower cumulative retention among ART enrollees (64% versus 50%). Cumulative linkage-to-care was low and should be prioritized for improvement. Variations in outcomes by arrondissement and between adults and children require further investigation and programmatic response.