A group of 26 patients (18 males and 8 females) infected with HIV (42% through sexual route and 58% through blood/blood products transfusion) was prospectively studied to assess the efficacy of low doses (300 mg/day) of AZT combined (n = 15) or not (n = 11) with ACV (600 mg/day). According to CDC stages, 12% were in stage II, 73% in stage III and 15% in stage IV. Patients were followed for a maximum of 156 weeks. An objective response was observed in all patients who improved significantly in: performance status (Karnofsky 74.5 versus 97.6%, p less than 0.01), weight 58.9 versus 68.6 kg, p less than 0.01), and absolute CD4 T cell count (329/microL versus 480/microL, p less than 0.01). The levels of hemoglobin dropped after treatment (12.8 versus 11.5, p less than 0.01). Median survival was 114 weeks for all the group. With the exception of granulocytopenia in 42% of patients treated with AZT + ACV versus only in 22% of those treated solely with AZT (p = 0.02), similar effects were recorded in both treatments: 114-week survival was 60% for those treated solely with AZT, whereas 156-week survival was 93% for those treated with AZT + ACV (p NS), but the response was better for the combination of antivirals in the group of patients with more than 200 CD4 cells/microL at diagnosis as compared with those with less than 200 cells (110-week survival of 100% versus 50% respectively).(ABSTRACT TRUNCATED AT 250 WORDS)