This study was designed to compare the efficacy, tolerability, and safety of the combination valsartan/amlodipine 160/5 mg versus amlodipine 10 mg in patients with essential hypertension not adequately controlled (defined as mean sitting systolic blood pressure [msSBP] ≥ 130 mmHg and ≤ 160 mmHg) on amlodipine 5 mg alone. The study evaluated both the efficacy and tolerability of the treatments by providing data that assessed blood pressure and the proportion of patients developing peripheral edema.