OBJECTIVES: We performed a meta-analysis to determine the overall effectiveness of statins among hypertensive and non-hypertensive patients. METHODS: We systematically reviewed Medline publications from 1985 onwards for placebo-controlled randomized trials that examined the effect of statins on cardiac morbidity and mortality. Only trials that followed at least 1000 patients for two or more years were included in the meta-analysis. Outcomes of interest included cardiac or cardiovascular death, major coronary events, or major cardiovascular events. Pooled estimates of relative risk were calculated separately for (i) trials that prospectively randomized hypertensive patients to statin therapy (ASCOT-LLA & ALLHAT-LLT); (ii) trials that provided post-hoc cardiac event rates for subgroups of hypertensive patients and non-hypertensive patients; (iii) trials that provided only the baseline percentage of hypertension in the trial population; and (iv) trials in (ii) and (iii) combined. The moderating effect of the percentage of hypertensive patients at baseline on the effectiveness of statins was tested using meta-regression. RESULTS: Besides the ASCOT-LLA and ALLHAT-LLT, 12 trials enrolling a total of 69,984 patients met the inclusion criteria. Overall, in these 12 trials, statin therapy reduced cardiac death by 24% (relative risk [RR]: 0.76; 95% confidence interval [CI]: 0.71 - 0.82). Pooled relative risk for cardiac morbidity and mortality was similar for trials in groups i, ii, iii, and iv and ranged from 0.73 - 0.78. Relative risk estimates for hypertensive patients (RR: 0.78; 95% CI: 0.72 - 0.84) and non-hypertensive (RR: 0.76; 95% CI: 0.72 - 0.80) subgroups were also similar. Consistent with the subgroup analysis, the meta-regression showed that the effect of statins on cardiac morbidity and mortality was not moderated by the percentage of hypertensive patients at baseline (Q estimate = 1.48; P = 0.22). CONCLUSION: Statin therapy effectively reduces CV morbidity and mortality in both hypertensive and non-hypertensive patients.