In previous beta-blocker trials, post-myocardial infarction (MI) patients were essentially treated with a beta-blocker or placebo. In the CAPRICORN trial, patients were selected on the basis of a left ventricular (LV) ejection fraction (EF) <40% following the index MI and randomised to carvedilol or placebo, in addition to modern secondary prophylaxis with ACE inhibitors, aspirin and statins. In 1959 patients with a mean LVEF of 33%, treatment with carvedilol over a mean follow-up period of 15 months reduced total mortality from 15.3% with placebo to 11.9% with carvedilol [relative risk reduction (RRR) =23%, absolute risk reduction (ARR) =3.4%]. The incidence of recurrent MI was reduced from 5.8 to 2.3% (RRR 41%, ARR 2.3%). The number needed to treat (NNT) to prevent one death was 28 for the entire study period and 43 for 1 year of treatment. The results of the CAPRICORN trial are compared with three previous beta-blocker post-MI trials: the Gothenburg metoprolol trial (GMT), the Norwegian timolol trial (NTT) and the beta-blocker heart attack trial (BHAT). The RRRs for total mortality were 36% in the GMT and NTT, and 27% in BHAT. The respective NNTs for total mortality were 32, 18 and 38. NNT for 1 year of treatment was 25 in NTT and 80 in BHAT. The RRR for recurrent MIs were 28% in NTT and 16% in BHAT. The reduction of mortality and recurrent MIs in CAPRICORN is within the range of previous post-MI beta-blocker studies. In post-MI patients with LVEF<40%, add-on treatment with a beta-blocker should be given >48 h after initiation with an angiotensin-converting enzyme inhibitor (ACEI) and then with a slow dose escalation as applied in CAPRICORN.