Although treatment with zidovudine significantly reduces the likelihood of mother-to-infant transmission of the human immunodeficiency virus (HIV), 1 perinatally acquired infections still account for the majority of new cases of the acquired immunodeficiency syndrome (AIDS) in children. 2 , 3 Zidovudine has been the recommended treatment for these children, but controlled trials have not been conducted to compare it with other antiretroviral agents or combination therapies in children. Recent studies in adults suggest that combination antiretroviral regimens, particularly those including protease inhibitors, may prolong the period of HIV nonprogression, 4 but comparable studies have not been done in children. In this study, we compared . . .