BACKGROUND Although many studies have indicated that psychosocial factors contribute to hypertension, and that early childhood adversity is associated with long-term adverse mental and physical health sequelae, the association between early adversity and later hypertension is not well studied. METHOD Data from 10 countries participating in the World Health Organization (WHO) World Mental Health (WHM) Surveys (N = 18,630) were analyzed to assess the relationship between childhood adversity and adult-onset hypertension, as ascertained by self-report. The potentially mediating effect of early-onset depression-anxiety disorders, as assessed by the WHM Survey version of the International Diagnostic Interview (WMH-CIDI), on the relationship between early adversity and hypertension was also examined. RESULTS Two or more early childhood adversities, as well as early-onset depression-anxiety, were significantly associated with hypertension. A range of specific childhood adversities, as well as early-onset social phobia and panic/agoraphobia, were significantly associated with hypertension. In multivariate analyses, the presence of 3 or more childhood adversities was associated with hypertension, even when early-onset depression-anxiety or current depression-anxiety was included in the model. CONCLUSIONS Although caution is required in the interpretation of self-report data on adult-onset hypertension, the results of this study further strengthen the evidence base regarding the role of psychosocial factors in the pathogenesis of hypertension.