We study whether childhood health capital affects school attendance, long-run occupational outcomes, and intergenerational mobility. We address this question in the context of London, England during the late nineteenth century using the inpatient admission records of three large hospitals linked to population census records, from which we identify household characteristics and the patients' siblings. Sibling fixed effects estimates indicate that boys with health deficiencies were 14.9 percent less likely to work in white collar occupations as adults and 13.9 percent more likely to experience downward occupational mobility relative to their fathers, in comparison to their brothers. This negative effect offsets 16.2 percent of the benefit of having a father in a high status occupation. We also explore medium-run mechanisms for both boys and girls, and find that poor childhood health reduced the likelihood of attending school by 2.5 and 4.1 percent, respectively. [Funding was provided by the Hitotsubashi Institute for Advanced Study, Hitotsubashi University, and the Economic History Association.]