We use unique administrative German data to examine the role of childhood health for the intergenerational transmission of human capital. Specifically, we examine the extent to which a comprehensive list of health conditions – diagnosed by government physicians – can account for developmental gaps between the children of college educated parents and those of less educated parents. In total, health conditions explain 18% of the gap in cognitive ability and 65% of that in language ability, based on estimations with sibling fixed effects. Thus, policies aimed at reducing disparities in child achievement should also focus on improving the health of disadvantaged children.