Little is known about immunologic reconstitution in children on highly active antiretroviral treatment (HAART) during very long-term periods. A retrospective study was carried out to assess the effectiveness and development of metabolic disorders after very long-term periods on HAART in HIV-infected children with severe immunodeficiency. We included 55 children who were stratified into three groups according to %CD4(+) pre-HAART and rate of immunologic recovery: (1) S1-Rec: CD4(+) < or =5% at baseline and slow immunologic recovery; (2) S2-Rec: CD4(+) 5-15% at baseline and slow immunologic recovery; (3) R-Rec: CD4(+) < or =15% at baseline and rapid immunologic recovery (reference group). An adequate immune recovery after 8 years on HAART was achieved by only 25% of children. S1-Rec never achieved a mean of CD4(+) > or =25% after 8 years on HAART. All children had a significant increase in plasma cholesterol levels during the first 2 years. Afterward, cholesterol levels reached a plateau and remained stable until year 8 of follow-up. Higher rates of lipodystrophy were found in the R-Rec group [14 (100%)] than in the S1-Rec group [9/19 (47.4%)] or the S2-Rec group [13/20 (65%)] at the end of the study (p = 0.006). Overall, having a low nadir of CD4(+) hindered immune reconstitution; however, children with rapid immunologic recovery showed a higher prevalence of the lipodystrophy syndrome.