Delivering early-childhood programs at scale is a major policy challenge. One way to do so is by using existing public infrastructure. This paper experimentally assesses the short-term effects of a new government home-visiting program integrated into health-care services in Brazil. The program changed the allocation of time for community health workers by asking them to carry out tasks related to early-childhood development. We find that access to the program has a positive but modest effect on home environment quality and no effect on child development or on children’s health status. Our results point to the importance of workload, supervision, and buy-in from delivery actors to enhance fidelity of interventions.