The effects on blood pressure of regular patient and professional monitoring of blood pressure, extensive patient-involved assessment of results, relaxation, and systolic blood pressure biofeedback are analyzed by comparisons of data from two 3-month treatment periods with results from a 1-month baseline period and by comparisons among control and treatment groups. Ninety borderline hypertensive patients completed the treatments. Major findings are: A Acute effects; 1) Both relaxation and systolic blood pressure biofeedback lowered blood pressure acutely. 2) Improvement in performance of relaxation and biofeedback with practice showed that they are learned skills. 3) Acutely, relaxation and biofeedback were equally effective for lowering systolic blood pressure, but relaxation lowered diastolic blood pressure more. B. Long-term effects; 1) Blood pressure declined for at least 6 months with regular monitoring and patient-involved assessment. 2) The greatest lowering of blood pressure by behavioral intervention occurred during periods when pressures tended to be highest. 3) A combination of relaxation and biofeedback, with biofeedback preceding relaxation, was better than either used alone and slightly, but not significantly, better than relaxation preceding biofeedback. 4) The long-term effects of biofeedback were slightly greater than those of relaxation. A staged, incremental behavioral treatment of borderline hypertension is proposed.