BACKGROUND: It is well recognized that patients with high blood pressure (hypertension) in the community frequently fail to meet treatment goals - a condition labeled as "uncontrolled" hypertension. The optimal way in which to organize and deliver care to patients who have hypertension so that they reach treatment goals has not been clearly identified. OBJECTIVES: To determine the effectiveness of interventions to improve control of blood pressure in patients with hypertension. To evaluate the effectiveness of reminders on improving the follow-up of patients with hypertension. SEARCH STRATEGY: All-language search of all articles (any year) in the Cochrane Controlled Trials Register (CCTR), Medline and Embase from June 2000. SELECTION CRITERIA: Randomized controlled trials (RCTs) of patients with hypertension that evaluated the following interventions: (1) self-monitoring (2) educational interventions directed to the patient (3) educational interventions directed to the health professional (4) health professional (nurse or pharmacist) led care (5) organisational interventions that aimed to improve the delivery of care (6) appointment reminder systems. Outcomes assessed were: (1) mean systolic and diastolic blood pressure( 2) control of blood pressure (3) proportion of patients followed up at clinic. DATA COLLECTION AND ANALYSIS: Two authors extracted data independently and in duplicate and assessed each study according to the criteria outlined by the Cochrane Collaboration Handbook. MAIN RESULTS: 56 RCTs met our inclusion criteria. The methodological quality of included studies was variable. An organized system of regular review allied to vigorous antihypertensive drug therapy was shown to reduce blood pressure (weighted mean difference -8.2/-4.2 mmHg, -11.7/-6.5 mmHg, -10.6/-7.6 mmHg for 3 strata of entry blood pressure) and all-cause mortality at five years follow-up (6.4% versus 7.8%, difference 1.4%) in a single large RCT- the Hypertension Detection and Follow-Up study. Other interventions had variable effects. Self-monitoring was associated with moderate net reduction in diastolic blood pressure (weighted mean difference (WMD): -2.0 mmHg, 95%CI: -2.7 to -1.4 mmHg, respectively. Appointment reminders increased the proportion of individuals who attended for follow-up. RCTs of educational interventions directed at patients or health professionals were heterogeneous but appeared unlikely to be associated with large net reductions in blood pressure by themselves. Health professional (nurse or pharmacist) led care may be a promising way of delivering care, with the majority of RCTs being associated with improved blood pressure control, but requires further evaluation. AUTHORS' CONCLUSIONS: Family practices and community-based clinics need to have an organized system of regular follow-up and review of their hypertensive patients. Antihypertensive drug therapy should be implemented by means of a vigorous stepped care approach when patients do not reach target blood pressure levels.