Although national clinical guidelines promulgate therapeutic lifestyle changes (TLC) as a cornerstone in the management of prehypertension, there is a perceived ineffectiveness of TLC in the real world. In this study of 2,478 ethnically diverse (African Americans n = 448, Caucasians n = 1,881) men (n = 666) and women (n = 1,812) with prehypertension and no known atherosclerotic cardiovascular disease, diabetes mellitus, or chronic kidney disease, we evaluated the clinical effectiveness of TLC in normalizing blood pressure (BP) without antihypertensive medications. Subjects were evaluated at baseline and after an average of 6 months of participation in a community-based program of TLC. TLC included exercise training, nutrition, weight management, stress management, and smoking cessation interventions. Baseline BP (125 +/- 8/79 +/- 3 mm Hg) decreased by 6 +/- 12/3 +/- 3 mm Hg (p <or=0.001), with 952 subjects (38.4%) normalizing their BP (p <or=0.001). In subjects with a baseline systolic BP of 120 to 139 mm Hg (n = 2,082), systolic BP decreased by 7 +/- 12 mm Hg (p <or=0.001). In subjects with a baseline diastolic BP of 80 to 89 mm Hg (n = 1,504), diastolic BP decreased by 6 +/- 3 mm Hg (p <or=0.001). There were no racial differences in the magnitude of reduction in BP; however, women had greater BP reductions than men (p <or=0.001). Also, subjects with a baseline body mass index (BMI) <30 kg/m(2) had a greater reduction in BP than those with a BMI >or=30 kg/m(2). In conclusion, the present study adds to previous research by reporting on the effectiveness, rather than the efficacy, of TLC when administered in a real-world, community-based setting.