Plasma virus load measurements, CD4 counts, and clinical evaluations were performed on 63 HIV infected children in the Fall of 1994, and follow-up assessments were performed in the Fall,1996. At baseline, the median age was 5.54 years [Range 0.36 to 13.4 years], median log RNA copy number: 4.78(60,256 copies/ml) [1.7-6.34], median CD4 percent: 23% [0-50]. At the time of follow-up, the medians were: Age 7.58 years, CD4 18%, and log viral RNA copy number 4.32 (20,892). 8 Patients died during the period of follow-up, 13 others developed a new CDC Category C diagnosis, 42 had neither. A comparison of the median baseline values for those who died /had a new category C Dx/ neither showed: Age [5.10 / 4.25 / 6.08 years] CD4% [2 / 7 / 27.5%] Log RNA[5.63 / 5.07 / 4.46]. 17 of the 21 children with a new category C or death had an initial RNA PCR >4.6 logs (50,000 copies/ml). Three of the 4 with bad outcomes and <4.6 log RNA had baseline CD4 counts of <50 cells/cmm. Conclusion: Both CD4 count and RNA copy number define children at risk for HIV progression. Children with HIV RNA copy numbers <4.6 log(50,000 copies/ml) are unlikely to show progression within a 2 year period of follow-up, and the children with lower RNA numbers who are at risk of progression generally have low CD4 counts.Funded by NIAID AIDS Clinical Trials Group and Glaxo Wellcome, Co.