CONTEXT: The physical health consequences of childhood psychosocial adversities may be as substantial as the mental health consequences, but whether this is the case remains unclear because much prior research has involved unrepresentative samples and a selective focus on particular adversities or physical outcomes. The association between early-onset mental disorders and subsequent poor physical health in adulthood has not been investigated. OBJECTIVE: To investigate whether childhood adversities and early-onset mental disorders are independently associated with increased risk of a range of adult-onset chronic physical conditions in culturally diverse samples spanning the full adult age range. DESIGN: Cross-sectional community surveys of adults in 10 countries. SETTING: General population. PARTICIPANTS: Adults (ie, aged ≥18 years; N = 18 303), with diagnostic assessment and determination of age at onset of DSM-IV mental disorders, assessment of childhood familial adversities, and age of diagnosis or onset of chronic physical conditions. MAIN OUTCOME MEASURES: Risk (ie, hazard ratios) of adult-onset (ie, at age >20 years) heart disease, asthma, diabetes mellitus, arthritis, chronic spinal pain, and chronic headache as a function of specific childhood adversities and early-onset (ie, at age <21 years) DSM-IV depressive and anxiety disorders, with mutual adjustment. RESULTS: A history of 3 or more childhood adversities was independently associated with onset of all 6 physical conditions (hazard ratios, 1.44 to 2.19). Controlling for current mental disorder made little difference to these associations. Early-onset mental disorders were independently associated with onset of 5 physical conditions (hazard ratios, 1.43 to 1.66). CONCLUSIONS: These results are consistent with the hypothesis that childhood adversities and early-onset mental disorders have independent, broad-spectrum effects that increase the risk of diverse chronic physical conditions in later life. They require confirmation in a prospectively designed study. The long course of these associations has theoretical and research implications.