General strain theory provides one framework for explaining the relationship between physical health and delinquency, pointing to mechanisms such as negative emotions, social bonds, and stress proliferation. Data from the National Longitudinal Study of Adolescent Health were used to examine these hypothetical mediators. Controlling for demographic factors, prior illicit behavior, and other strains, results from a series of regressions indicated that health-related strain (HRS) was positively associated with subsequent delinquency and marijuana use. Stressors at school were the primary mediators of these effects. Absences from school and social life due to health problems exerted an independent effect. The results lend support to the idea that experiencing HRS contributes to the proliferation of stress in other life domains, increasing the likelihood of delinquency and marijuana use.