OBJECTIVE To evaluate the use of cardiovascular medications in patients with and without heart failure after myocardial infarction (MI). DESIGN AND SETTING Multicentre study of drug therapy for patients with MI in 16 major metropolitan teaching hospitals in Australia over a 1-month period at each hospital in the period November 2004 - March 2005. PARTICIPANTS 479 patients admitted consecutively to the individual hospitals. MAIN OUTCOME MEASURES Proportion of patients with and without heart failure who were prescribed key cardiovascular medications after MI. RESULTS 116 of the 479 patients admitted for MI (24.2%) had heart failure at some point during their hospitalisation. Patients with heart failure were older (68 v 63 years; P < 0.05), more likely to be women (34% v 24%; P < 0.05) and a higher proportion had diabetes (26% v 21%). There was significantly reduced prescribing of beta-blockers, clopidogrel and statins for patients with heart failure compared with those without heart failure. Mineralocorticoid receptor antagonist use was low (< 10%) in the former group. CONCLUSIONS We found reduced prescribing of some prognostically relevant medications for patients with heart failure. For beta-blockers, this may be explained by the greater clinical instability in patients with heart failure. Given the absolute benefit of drug therapy in patients with heart failure after MI, our findings suggest suboptimal prescribing in Australian teaching hospital practice.