Chronic cardiac failure is an important problem of public health because of its prevalence and high mortality. A better understanding of its physiopathology and the detrimental effect of neurohormonal activation that it induces were the reasons for the utilisation of angiotensin converting enzyme inhibitors leading to symptomatic improvement and also a reduction in the mortality of severe cardiac failure, as demonstrated in the CONSENSUS study published 5 years ago. Since then, cardiologists have presented ACE inhibitors in all stages of cardiac failure, but is this attitude justified? More explicitly, are ACE inhibitors the drugs of choice in cardiac failure? Before acknowledging this label "drug of choice" in the treatment of chronic cardiac failure, ACE inhibitors should fulfill certain reference criteria proposed by Packer for the treatment of this condition: rapid relief of symptoms; reduced mortality; modification of the natural history of the condition; efficacious and well tolerated. The effects of ACE inhibitors are analysed critically taking into account the results of large scale therapeutic trials (SOLVD, V-HeFT II, CONSENSUS II, SAVE), which have been reported recently? The reported results confirm clinical impressions: ACE inhibitors are the drugs of choice of all stages of chronic cardiac failure but in association with diuretic and digitalis therapy.