The purpose of this study is to evaluate the efficacy of valsartan plus amlodipine in hypertensive patients not responding to treatment with amlodipine or felodipine alone.

Inclusion Criteria:

1. Male or female patients (18 years)
2. Patients with moderate essential hypertension (untreated must have MSSBP ≥160 and <180 mmHg at Visit 1, treated must have MSSBP <180 mmHg at Visit 1) (WHO grade II)

Exclusion Criteria:

1. Severe hypertension(MSDBP ≥110 mmHg or MSSBP ≥ 180 mmHg)
2. Pregnant or nursing women
3. Treated hypertensive patients with controlled hypertension under current therapy (diastolic BP < 90 mmHg and systolic BP < 140 mmHg)
4. A history of cardiovascular disease, including angina pectoris, myocardial infarction, coronary artery bypass graft, percutaneous transluminal coronary angioplasty, transient ischemic attack, stroke, and heart failure NYHA II - IV

Other protocol-defined inclusion/exclusion criteria may apply.