We assess the impacts of a randomized school-based deworming intervention in Kenya on the mortality of recipients’ children using a 23-year longitudinal data set of over 6,500 original participants and their offspring. The under-5 mortality rate fell by 22% (17 deaths per 1000 live births) for children of treatment group individuals. We find that a combination of improved health, education, and living standards, increased urban residence, delayed fertility, and greater use of health care in the parent generation contributed to the reduction. The results provide evidence for meaningful intergenerational benefits of child health investments