AZT has been shown to decrease the death rate and frequency of opportunistic infections in certain adult patients with symptomatic HIV infection. Thus, it is likely that symptomatic HIV infected children may also benefit from AZT. Studies of the safety and pharmacokinetics (blood levels) in children have indicated that AZT can be given to children in doses that can be tolerated and that can be assumed to be therapeutic. Those currently taking care of infected children no longer feel it is ethical to conduct an AZT/placebo (inactive substance) trial. In addition, given the information learned from studies of adult patients that shows effectiveness of AZT at lower doses, experience with an equivalent lower dose in children needs to be studied.