All patients receive combination antiretroviral therapy with didanosine (ddI), stavudine (d4T), efavirenz (EFV), and nelfinavir (NFV). Patients are randomized to self-administered (SAT) versus observed (MAT) therapy for 24 weeks. Patients randomized to MAT receive one directly observed dose (ddI, d4T, EFV, and NFV) of their antiretroviral regimen by a field worker or nurse at the clinic 5 days per week. As a reminder for the second NFV and d4T dose, MAT patients are provided with an alarm watch programmed to sound at dosing times. The alarm watch also serves as a reminder for weekend doses that will not be directly observed. Patients randomized to SAT receive standard care. All patients are monitored with monthly plasma HIV RNA levels and CD4 and CD8 cell counts. At Week 24, all patients are crossed over to SAT for an additional 48 weeks of follow-up.