OBJECTIVE The paucity of data on myocardial infarction management and results in Spain lead to the design of the PRIAMHO study (Proyecto de Registro de Infarto Agudo de Miocardio Hospitalario [Acute Myocardial Infarction Hospital Registration Project]) which developed standard methods to collect information on the management of patients with such a condition and their characteristics. The variability results among hospitals in myocardial infarction management and in one-year mortality are presented. METHODS A cohort study with a one-year follow-up was designed to register all patients diagnosed with acute myocardial infarction discharged from 24 Spanish hospitals that completed all the requisites to participate. The demographic and clinical characteristics of the patients, their management during the coronary care unit stage, and the outcome and complications were prospectively registered. Standard definitions for diagnosis were used. Confidentiality regarding patient identity and participating centers was guaranteed. RESULTS 5,242 (77.6%) of the 6,756 patients with myocardial infarction admitted in the 24 participating hospitals were registered in the coronary care units. Half of the centers had an on-site hemodynamic laboratory and in seven coronary surgery. The delay between symptom-onset and emergency room admission was 2 hours. Acute pulmonary edema or cardiogenic shock was developed by 16.6% of patients and 41.8% received thrombolysis. Mean time delay between symptom-onset and thrombolysis was 3 hours. A large variability in the use of beta-blockers, thrombolysis, echocardiography, coronary catheterization angiography and invasive revascularization was observed among hospitals. Mortality in the coronary care unit was 10.9% and increased to 14.0% at 28 days and to 18.5% at one year with considerable variation among hospitals. Four hospitals showed higher mortality among their patients, independently from the proportion of diabetes, hypertension, women, anterior location of myocardial infarction, non-Q-wave infarction, age and severity. CONCLUSIONS The results of this study show that early and mid-term mortality from myocardial infarction is still high in Spain in the reperfusion era, and that a considerable variability in management and outcome exists among Spanish hospitals, which is not explained by the different case-mix among them.