The hypothesis of this study was that specific lifestyle patterns would be predictive of, or increase the risk for, uncontrolled hypertension in drug-treated hypertensive subjects. By means of a previously validated questionnaire, alcohol consumption, smoking, exercise, calcium intake, sodium intake, caffeine intake, body weight pattern and perceived stress level were evaluated in 364 subjects who attended a hypertension clinic in a large urban teaching hospital. The subjects were divided into controlled and uncontrolled categories on the basis of a clinic blood pressure reading. The number of prescribed drugs was not different between the two groups. Stratified analysis identified a high perceived stress level, a high calcium intake, and a lower body mass index as predictive of uncontrolled hypertension. Other variables showed no significant correlation. The conclusion of the study is that traditional risk factors for hypertension may assume less importance in drug-treated hypertensive patients than in untreated hypertensive patients.