BACKGROUND: In Latin America, the first wave of HIV-infected patients initiated highly active antiretroviral therapy (HAART) 10 or more years ago. Characterizing their treatment experience and corresponding outcomes across a decade of HAART may yield insights relevant to the ongoing care of such patients and those initiating HAART more recently in similar clinical settings. METHODS: This retrospective study included adults initiating HAART before 2004 at 8 sites in Argentina, Brazil, Chile, Haiti, Honduras, and Mexico. Patient status (in care, dead, or lost to follow-up [LTFU]) was assessed at 6-month intervals for 10 years, along with CD4 count and HIV-1 viral load (VL) for patients in care. RESULTS: 4,975 patients (66% male) started HAART prior to 2004; 45% were not antiretroviral-naïve. At 1, 5, and 10 years, rates of mortality were 4.2%, 9.0%, and 13.6% respectively. LTFU rates for the same periods were 2.4%, 10.9%, and 24.2%. Among patients remaining in care at 10 years, 84.4% were estimated to have VL≤400 copies/mL (Haiti excluded) and median baseline CD4 increased from 158 to 525 cells/mm3. Only 11.4% of all patients remained on their first regimen, 12.6% were on their second, 11.5% were on their third, and 23.0% were on their fourth or subsequent regimen. Outcomes were generally better for patients who were not antiretroviral-naïve, except for viral suppression. Heterogeneity among sites was substantial. CONCLUSIONS: Despite advanced disease and predominant use of older antiretrovirals, a large percentage of early HAART initiators in this Latin American cohort were alive and in care with sustained virologic suppression and progressive immune recovery after 10 years.