Arterial stiffness is an independent cardiovascular prognostic factor and is modulated by angiotensin-converting enzyme inhibitors (ACEIs). The authors performed a meta-analysis of clinical trials investigating the effects of ACEIs on pulse wave velocity (PWV) or augmentation index. The search included randomized clinical trials as well as uncontrolled studies that measured in-treatment changes in arterial stiffness. The authors performed separate analyses for carotid-femoral PWV, brachioradial PWV, and augmentation index. Average absolute and relative reduction in mean arterial pressure and PWV were −15.4 mm Hg and −13.04% and −1.15 mis and -9.74% for carotid-femoral PWV studies; and −11.2 mm Hg and -9.3% and −1.9 mis and −16.7% for brachioradial PWV studies. There was a greater reduction in augmentation index by ACEIs when compared with controls (—1.0% to −5.3%). The authors conclude that ACEIs have modest beneficial effects on arterial stiffness measured as PWV and augmentation index, and this effect is at least partly independent of changes in blood pressure.