UNLABELLED: Lamivudine and zidovudine are proving to be an important antiretroviral combination against HIV that is superior to monotherapy. Recently, with the appearance of protease inhibitors, ritonavir has been shown to be a powerful drug when used in combination with reverse transcriptase inhibitors. The objective of this study was to observe the efficacy, adverse events, and changes in the quality of life of AIDS patients receiving treatment for the first time using AZT, 3TC and ritonavir as combination therapy. We selected 36 patients diagnosed with AIDS due to opportunistic infections and evaluated them by assessing their score on quality of life scales (Karnofsky, uniscale - Quality of Life, and Quality of Life Scale), T CD(4) and CD(8) lymphocyte counts, bodyweight and symptoms during a 6 month period. Assessments were made at 2 month intervals. One patient was excluded from the trial, therefore, 35 were assessed during 6 months. RESULTS: Bodyweight increased an average of 7.2%, CD(4) increased 260 cells/mm(3) and CD(8) increased 198 cells/mm(3). The Karnofsky and uniscale QOL scales reached 100% on the fourth visit. The Quality of Life Scale showed an important increase during this study from 5.5+/-2.3 to 9.7+/-0.5. Adverse events were observed in 25.0% of the patients, most being slight. One patient had to stop taking ritonavir due to nausea and vomiting. We conclude that AZT, 3TC, and ritonavir restored the quality of life for the AIDS patients studied in terms of psychosocial aspects and overall health conditions during 6 months of treatment. The adverse events were probably related to ritonavir, but they were slight and disappeared after 2 weeks. There was a significant increase in the average number of CD(4) lymphocytes during 6 months of treatment.