Since 1) renin-angiotensin-aldosterone systems play an critical role in the development and progression of chronic heart failure, and 2) inhibitors of angiotensin converting enzyme (ACEIs) are proved to be effective for the treatment of chronic heart failure, angiotensin II receptor antagonists may be more effective than ACEIs. This is because angiotensin II receptor antagonists can inhibit the effects of angiotensin II via ACE-independent pathways, e.g., chymase. On the other hand, ACEIs can increase bradykinin, and thus, nitric oxide, which may cause potent cardioprotection. Therefore, angiotensin II receptor antagonists and ACEIs may mediate cardioprotection via different mechanisms, which may hint the combination therapy of both drugs in the pathophysiology of chronic heart failure. Angiotensin II receptor antagonists may open a new era for the treatment of chronic heart failure.