Blood pressure-lowering therapy reduces left ventricular mass, but the question of whether differences exist among drug classes has not been fully resolved. Our aim was to compare the effects of diuretics, beta-blockers, calcium channel blockers, angiotensin-converting enzyme inhibitors, and angiotensin receptor blockers on left ventricular mass regression in patients with hypertension on the basis of prospective, randomized comparative studies. We performed meta-analyses, involving pooled pairwise comparisons of the drug classes and of each class versus other classes statistically combined, and meta-regression analyses to identify the determinants of the regression. The 75 relevant publications involved 84 pairwise comparisons and 6001 patients. Regression of left ventricular mass was significantly less (P=0.01) with beta-blockers (9.8%) than with angiotensin receptor blockers (12.5%), but none of the other analyzable pairwise comparisons between drug classes revealed significant differences (P>0.10). In addition, beta-blockers showed less regression than the other 4 classes statistically combined (P<0.01), and regression was more pronounced with angiotensin receptor blockers versus the others (P<0.01). In multivariable meta-regression analysis on all of the treatment arms, beta-blocker treatment was a significant and negative predictor of the regression (-3.6%; P<0.01), but this was not the case for the other drug classes, including angiotensin receptor blockers. In conclusion, beta-blockers show less regression of left ventricular mass, whereas angiotensin receptor blockers may induce larger regression. The inferiority of beta-blockers appears to be more convincing than the superiority of angiotensin receptor blockers.