Background: Combining statins with antihypertensive therapy has been demonstrated to provide an early reduction in cardiovascular events. This nested substudy of the AVALON trial assessed the effects of coadministered amlodipine and atorvastatin vs. either therapy alone or placebo on arterial compliance, to evaluate the vascular benefits of coadministered therapy. Methods: During an initial 8-week, double-blind phase, patients with concomitant hypertension and dyslipidemia were randomized into four treatment groups (placebo, amlodipine 5 mg, atorvastatin 10 mg, or coadministered amlodipine 5 mg and atorvastatin 10 mg). The sustained effect of combined therapy was evaluated during subsequent 8-week, single-blind, and 12-week, open-label periods. In the single-blind phase, all patients were coadministered amlodipine 5 mg and atorvastatin 10 mg, which were then titrated to optimize blood pressure and low-density lipoprotein cholesterol control during the open-label phase. Arterial compliance was assessed every 4 weeks using the HDI/Pulsewave CR-2000. Results: Overall, 668 patients (61% male, mean age 55 years) were randomized to treatment. A 19% improvement in small artery compliance (C2) was observed with coadministered amlodipine and atorvastatin from baseline to week 8, which was significantly greater than with either treatment alone or with placebo (P = 0.03 to 0.0001). After 28 weeks, C2 was increased from baseline in all groups, but the overall improvement was greatest in the group receiving coadministered drugs for the entire study period (P < 0.05). Conclusions: Early and sustained improvement in small artery compliance was observed following coadministration of amlodipine and atorvastatin, thus demonstrating a vascular benefit with simultaneous treatment of hypertension and dyslipidemia.