Child health and nutrition are strongly associated with educational achievement. But associations do not necessarily indicate causality; estimates generally are likely to be biased in one direction or the other, As a result analysts and policymakers should have much less confidence in findings about the effect of health on schooling success than has been claimed in previous surveys. The evidence is more nuanced and qualified than is often recognized but may still support the conclusion that health may have considerable effects on postschooling productivity. Policy implications point coward providing public subsidies for the collection, analysis, and dissemination of information about the links between health and education; and toward providing services to improve the health of poor children.