Converting enzyme inhibitors constitute a major advance in the management of patients with congestive heart failure (CHF). Not only do they improve the hemodynamics of these patients, but they also prolong the survival. Certain patients with CHF, however, may not tolerate conventional converting enzyme inhibitors because of hypotension, renal dysfunction or other side effects. Perindopril is a third generation converting enzyme inhibitor that produces profound and prolonged angiotensin-converting enzyme (ACE) inhibition (24 h after a single dose). Despite a more sustained ACE inhibition than captopril and enalapril, perindopril is devoid of the first dose hypotensive effects noted with these other drugs. Furthermore, several studies of perindopril in CHF showed serum creatinine and urea to remain stable, reflecting favourable renal tolerance. This is in contrast to the modest decrease in renal function observed with most other converting enzyme inhibitors.