OBJECTIVE--To assess the use of acute coronary care facilities in the Republic of Ireland with regard to case mix, patient characteristics, mortality and factors associated with mortality, time intervals to admission, utilisation of thrombolysis, and risk factor profiles. DESIGN--A 1 week prospective census of all hospitals admitting acute coronary cases. These comprised 23 coronary care units (CCU) and 17 combined coronary care/intensive care units (CCU/ICU). Data were collected by standardised methods on each new patient "upon whom a cardiac monitor was placed". RESULTS--Acute coronary heart disease was confirmed in 185 (44.9%) of 412 patients. Of these 109 (26.4%) had a confirmed myocardial infarction and 76 (18.4%) unstable angina. Women were significantly older than men in all groups. Of those with proven acute coronary heart disease, 42.6% were current smokers, 23.1% were aware of having a raised cholesterol concentration, and 42.3% gave a history of prior hypertension. Only 44% were transported by ambulance. Median delay time from the onset of symptoms to admission was 6 h in Dublin and 4 h elsewhere. 34.9% of patients with a confirmed myocardial infarction received thrombolysis. Mortality of patients with myocardial infarction CCU/ICU at 7 days was 10.9 %. CONCLUSIONS--There is potential for considerable improvement in the management of coronary heart disease in the Republic of Ireland through a reduction in delay times to admission to hospital, increased use of thrombolytic treatment, and intensification of advice on primary and secondary risk factors.