OBJECTIVE: This study was an effort to clarify both the psychological contributions to and the long-term consequences of uncomplicated essential hypertension. METHOD: The subjects were 193 healthy college students selected as sophomores and prospectively followed for over 50 years. Independent assessments of physical and mental health were made. RESULTS: Although objective indices of psychopathology predicted both physical morbidity and mortality, they did not predict hypertension. When pyknic somatotype, college diastolic blood pressure, and well- integrated personality in college were controlled, no other preadult variable predicted hypertension. As expected, heart disease, obesity, and alcohol abuse were each correlated with hypertension. After roughly 20 years, 14 of the 41 men with treated hypertension were in stable remission, and 13 men had developed cardiac complications. No differences between these groups could be discerned. CONCLUSIONS: Over time, hypertension appeared to be more a product of biological than of psychosomatic variables. Good psychological health did not diminish the risk of hypertension.