Systematic reviews of existing evidence show promising effects of community health worker (CHW) programs as a strategy to improve child survival, but also highlight challenges faced by CHW programs, including insufficient incentives to deliver timely and appropriate services. We assessed the effect of an incentivized community health delivery program in Uganda on all-cause under-five mortality. A cluster-randomized controlled trial, embedded within the scale-up of a new community health delivery program, was undertaken in 214 clusters in 10 districts in Uganda. In the intervention clusters micro entrepreneur-based community health promoters (CHPs) were deployed over a three-year period (2011-2013). On average 38 households were surveyed in each cluster at the end of 2013, for a total sample size of 8,119 households. The primary study outcome was all-cause under-five mortality (U5MR). U5MR was reduced by 27% (adjusted RR 0.73, 95% CI 0.58-0.93).