The purpose of this study is to assess the potential of using valsartan/HCTZ as initial therapy in patients with severe hypertension compared to valsartan alone as initial therapy, and to determine whether a greater proportion of patients achieve blood pressure control with the combination compared to the monotherapy without producing an unacceptable adverse event profile.

Inclusion Criteria:

• Diagnosed severe hypertension

Exclusion Criteria:

• Inability to discontinue all prior antihypertensive medications
• Heart failure of any kind
• History of stroke, transient ischemic attack, myocardial infarction, chest pain, abnormal heart rhythm Liver, kidney, or pancreas disease
• Diabetes with poor glucose control
• Allergy to certain medications used to treat high blood pressure

Other protocol-defined exclusion criteria may apply.