OBJECTIVES:: In this study we examine whether adolescents treated for HIV/AIDS in Southern Africa can achieve similar treatment outcomes to adults. DESIGN:: We have used a retrospective cohort study design to compare outcomes for adolescents and adults commencing ART between 2004 and 2010 in a public sector hospital clinic in Bulawayo, Zimbabwe. METHODS:: Cox proportional hazards modelling was used to investigate risk factors for death and loss to follow-up (LTFU) (defined as missing a scheduled appointment by ≥3months). RESULTS:: 1,776 adolescents commenced ART, 94% having had no previous history of ART. The median age at ART initiation was 13.3 3/19/2013years. HIV diagnosis in 97% occurred after presentation with clinical disease and a higher proportion of adolescents had advanced HIV disease at presentation compared to adults (WHO Stage 3/4 disease (79.3% vs 65.2% (p < 0.001)). Despite this, adolescents had no worse mortality than adults, assuming 50% mortality among those LTFU (6.4 vs 7.3 per 100 person years (pys), p = 0.75) with rates of loss to follow up significantly lower than in adults (4.8 vs 9.2 per 100pys, p < 0.001). Among those who remained actively followed after 5 years of follow up, 5.8% of adolescents switched to a second line regimen as a result of treatment failure, compared to 2.1% of adults (p < 0.001). CONCLUSIONS:: With adolescent-focused services, it is feasible to achieve good outcomes for adolescents in large-scale ART programs in Sub Saharan Africa. However, adolescents are at high risk of treatment failure, which compromises future drug options. Interventions to address poor adherence in adolescence should be prioritised.