Abstract Objective The effectiveness of leaf concentrate powder (LCP) as a nutritional supplement was established in trials conducted among adolescent girls and pregnant women in India. Here we evaluate LCP, compared with skimmed milk powder (SMP), as a supplement for antiretroviral-naïve children living with HIV in a sub-Saharan African country. Design Randomized controlled, two-arm, 6-month trial comparing effects of isoproteic (5 g) LCP (10 g daily) and SMP (15 g daily) on HIV-1 viral load, CD4 + cell count/percentage, weight/height-for-age, general blood parameters, diarrhoea, respiratory and HIV-related opportunistic infections. Setting Bujumbura and Kirundo, Burundi. Subjects Eighty-three HIV-positive, antiretroviral-naïve children aged 5–14 years: median (range) CD4 + count, 716 (361–1690) cells/mm 3 ; log 10 HIV-1 viral load, 4·39 (1·79–6·00). Results LCP was equivalent to SMP in relation to HIV-specific blood parameters and did not demonstrate superiority over SMP in relation to Hb. Three children in each arm (LCP, 7·1 % (3/42); SMP, 7·3 % (3/41)) proceeded to antiretroviral therapy because their CD4 + counts fell below 350 cells/mm 3 . Children in the LCP group reported higher levels of appetite and overall health at 6 months. There were no differences in clinical events or any other outcome measures. LCP was less palatable than SMP to the children in this population, but there were few negative perceptions of appearance, texture and taste. Conclusions LCP appears to be equivalent to SMP as a nutritional supplement in this population, despite slightly lower palatability. In relation to viral load and CD4 + count, equivalence may indicate no effect in either group. Effectiveness relative to no supplementation remains to be determined.