The objective of this open-label trial is to evaluate the virological and immunological effects of triple therapy with stavudine (40 mg twice daily if > or = 60 kg, 30 mg twice daily if < 60 kg)/didanosine (400 mg once daily if > or = 60 kg, 300 mg once daily if < 60 kg)/nevirapine (200 mg daily from day 1 to 14, then 200 mg twice daily) in 60 antiretroviral-naive HIV-infected adults with CD4 cell counts > or = 200 cells/mm3 and plasma HIV RNA > or = 5000 copies/ml. At present, 59 patients have begun receiving the trial regimen. Characteristics of patients at baseline were as follows: 46 men/13 women, CDC stage A, 75%; mean CD4 cell count, 429 cells/mm3; mean HIV RNA, 4.6 log10 copies/ml). Mean decrease of viral load was -1.9 log10 at week 4 (n = 39), -1.9 log10 at week 16 (n = 20), with HIV RNA below the detectable level (< 500 copies/ml) in 62% of patients at week 4 and 85% at week 16. Mean CD4 cell count increase was +118 cells/mm3 at week 4. Cutaneous intolerance occurred within the first 4 weeks in 11/59 (19%) patients after a mean of 14 days (range, 3-24 days) and led to nevirapine discontinuation in 3/11 patients. Preliminary results of this ongoing trial show that combination therapy with stavudine/didanosine/nevirapine is a convenient (seven pills in two daily intakes) triple-therapy regimen with rapid immunological and antiviral effects. Rash, frequent in the first weeks of therapy, usually can be managed without stopping nevirapine. Long-term suppression of plasma HIV RNA with this combination needs to be confirmed but may support use of nevirapine as a component of first-line anti-HIV therapy along with two nucleosides.