Quality of life (QOL) is an important antiretroviral treatment (ART) outcome. We compared QOL among 299 Thai and Cambodian children ages 1-12 years-old, CD4 15-24% randomized to early (ART at week 0, N = 149) versus deferred groups (ART when at CD4 < 15%, N = 150) and also compared with QOL data from age-matched healthy controls (N = 275). Primary caregivers completed PACTG QOL questionnaires at week 0 and every 24 weeks until 144 weeks. Children were enrolled during March 2006 to September 2008. Mean (SD) age of children was 6.3 (2.8) years, 58% were female, 60% were Thai, %CDC N:A:B:C was 2:62:36:0%. During 144 weeks, all children in the early-group and 69 (46%) of deferred-group children started ART. There was no significant difference of QOL scores between treatment groups at baseline (all p > 0.05) and at week 144 (all p > 0.05). By multivariate analysis, the early-group had higher QOL score changes in five domains, including health perception ( p = 0.04), physical resilience ( p = 0.02), psychosocial well-being ( p = 0.04), social and role functioning ( p < 0.01), and symptoms ( p = 0.01) compared to the deferred group. QOL of HIV-infected children in both groups were lower than healthy control in all 7 domains at baseline (all p < 0.05) and 5 of 7 domains at weeks 144 ( p < 0.01). In conclusion, no significant difference of QOL scores between treatment groups. Early ART commencement associated with greater increase of QOL scores over 144 weeks. QOL scores in HIV-infected children were lower than healthy controls.