The primary objective of this study is to compare the effectiveness of telmisartan 80 mg/hydrochlorothiazide 25 mg [Micardis HCT] to valsartan 160 mg/hydrochlorothiazide 25 mg [Diovan HCT] and placebo in the treatment of Stage 1 and Stage 2 hypertension.

Inclusion criteria

1. Ability to provide written informed consent.
2. Age 18 years or older.
3. Ability to stop current antihypertensive therapy without unacceptable risk to the patient (investigator's discretion).
4. Seated cuff DBP of 95 mmHg at Visit 2 (baseline).

Exclusion criteria

1. Pre-menopausal women (last menstruation 1 year prior to start of run-in period) who:

   • Are not surgically sterile and/or
   • Are nursing or pregnant
   • Are of child-bearing potential and are NOT practicing acceptable means of birth control, do NOT plan to continue using this method throughout the study and do NOT agree to submit to periodic pregnancy testing during participation in studies of > 3-months duration. Acceptable methods of birth control include oral, implantable, transdermal, or injectable contraceptives, and Intra-Uterine Device (IUD).

2. Known or suspected secondary hypertension.

3. Mean seated SBP >= 180 mmHg or mean seated DBP >= 120 mmHg during any clinic visit prior to randomization.

4. Hepatic and/or renal dysfunction as defined by the following laboratory parameters:

   • SGPT (ALT) or SGOT (AST) > 2 times the upper limit of normal range, or
   • Serum creatinine > 3.0 mg/dL or creatinine clearance < 0.6 ml/sec.

5. Bilateral renal artery stenosis, renal artery stenosis in a solitary kidney, post-renal transplant or with only one kidney.

6. Clinically relevant hypokalemia or hyperkalemia.

7. Uncorrected volume depletion.

8. Uncorrected sodium depletion.

9. Primary aldosteronism.

10. Hereditary fructose intolerance.

11. Biliary obstructive disorders, cholestasis or moderate to severe hepatic insufficiency.

12. Patients who have previously experienced symptoms characteristic of angioedema during treatment with ACE inhibitors or angiotensin II receptor antagonists.

13. History of drug or alcohol dependency within six months prior to start of run-in period.

14. Chronic administration of any medications known to affect blood pressure, etc.

15. Any investigational drug therapy within one month of start of run-in period.

16. known hypersensitivity to any component of the formulation study drugs (telmisartan, valsartan, HCT).

17. Contra-indication to a placebo run-in period (e.g. stroke within the past six months, MI, cardia surgery, PTCA or angina within the past three months prior to the start of run-in period.

18. Any other clinical condition which, in the opinion of the principal investigator, would not allow safe completion of the protocol and safe administration of telmisartan, valsartan, or HCT.

19. Night shift workers.

20. Clinically significant ventricular tachycardia, atrial fibrillation, atrial flutter or other clinically relevant cardiac arrhythmias as determined by the investigator.

21. NYHA functional class CHF III-IV.

22. Hypertrophic obstructive cardiomyopathy, aortic stenosis, hemodynamically relevant stenosis of aortic or mitral valve.

23. Patients whose diabetes has been unstable and uncontrolled for at least the past 3 months as defined by a HbA1c >/= 10%.

24. Concomitant use of lithium or cholestyramine or colestipol resins (potential drug interactions with HCT).

25. History of non-compliance with prescribed medication or protocol procedures.