This study is designed as a randomized, open trial of intermittent continuous infusions of Interleukin-2 in HIV seropositive patients with a CD4 cell count between 200 and 500 cells/mm(3). The goal of the study is to determine the optimal duration of each infusion, and the optimal interval between infusions. Thirty-six patients will be randomized to 3 groups: Group A will be the control group with a regimen of five day infusions of IL-2 every eight weeks; Group B will receive IL-2 infusions every eight weeks, however the duration of each infusion will be determined by parameters reflecting T cell proliferation, with discontinuation of each infusion at a point when the response appears to be maximized; Group C will receive five day infusions of IL-2; however the interval between infusions will be determined by the response seen to the prior infusion, with the goal of administering infusions while the CD4 cell count remains above baseline from the prior infusion. The dose of interleukin-2 to be used will be 9 MIU by continuous infusion daily. All patients will be evaluated at the NIH at least every 4 weeks, and at that time safety labs and immune studies will be performed. In addition, patients in Groups B and C will undergo a laboratory evaluation weekly, at which time immune parameters, including CD4 number and percent, spontaneous blast transformation, soluble IL-2 receptor levels, and viral parameters, including branched DNA assay and p24 antigen, will be determined. The study duration will be approximately one year.