OBJECTIVES: In children aged less than 15 years, to determine the cumulative proportion of deaths occurring within 3 and 6 months of starting split-tablet adult fixed-dose combination antiretroviral therapy (ART) and to identify risk factors associated with early deaths. DESIGN: A retrospective cohort analysis. METHODS: Data were collected and analysed from ART patient master cards and the ART register of all children registered for treatment between July 2004 and September 2006 in the ART clinic at Mzuzu Central Hospital, northern Malawi. RESULTS: A total of 439 children started on ART, of whom 220 (50%) were male; 37 (8%) were aged less than 18 months, 172 (39%) 18 months to 5 years, and 230 (52%) were 6-14 years. By September 2006, 49 children (11%) had died, of whom 35 (71%) died by 3 months and 44 (89%) by 6 months. The cumulative incidence of death at 3, 6, 12 and 24 months after ART was 8, 12, 13 and 15%, respectively. After multivariate analysis, being in World Health Organization clinical stage 4, having severe wasting and severe immunodeficiency were factors significantly associated with 3-month mortality and 6-month mortality, respectively. CONCLUSION: Although children do well on ART, there is high early mortality. Scaling up HIV testing and simple diagnostic tests for infants and children, expanding routine provision of cotrimoxazole prophylaxis, and investigating the role of nutritional interventions are three measures that, if implemented and expanded countrywide, may improve ART outcomes.