OBJECTIVES: This study was designed to quantitatively assess the effectiveness of self-practiced qigong for treatment of essential hypertension. METHODS: Six major electronic databases were searched up to July 2006 to retrieve any potential randomized controlled trials designed to evaluate the clinical effectiveness of self-practiced qigong for essential hypertension reported in any language, with main outcome measures as systolic blood pressure (SBP) and diastolic blood pressure (DBP). The quality of included studies were assessed with the Jadad Scale and a customized standard quality assessment scale. RESULTS: Ninety-two (92) studies were identified. Nine (9) of these studies qualified for meta-analysis, comprising a total of 908 cases. Results were as follows: (1) The mean decrease of SBP in those practicing qigong was a 17.03 mm Hg reduction (95% confidence interval (CI) 11.53-22.52) compared with nonspecific intervention controls, but not superior to that in drug controls (1.19 mm Hg, 95% CI -5.40-7.79) and conventional exercise controls (-1.51 mm Hg, 95% CI -6.98-3.95). (2) Mean decrease of DBP in those practicing qigong was 9.98 mm Hg (95% CI 2.55-17.41) compared with nonspecific intervention controls, but not superior to that in drug controls (2.49 mm Hg, 95% CI -0.16-5.13) and conventional exercise controls (-1.59 mm Hg, 95% CI -4.91-1.74). (3) No obvious side effects were identified. CONCLUSIONS: Self-practiced qigong for less than 1 year is better in decreasing BP in patients with essential hypertension than in no-treatment controls, but is not superior to that in active controls. More methodologically strict studies are needed to prove real clinical benefits of qigong, and to explore its potential mechanism.