This study aims at describing the in-hospital prognosis of patients admitted with suspected acute myocardial infarction, focusing on the possibility of emergency room prediction of the risk for death and severe complications. From 7157 consecutive patients with chest pain or other symptoms suggestive of acute myocardial infarction in the emergency room, 4690 were hospitalized. Of these, 246 (5%) died in hospital, with a mortality rate among the 921 patients who developed myocardial infarction of 14%, and among those without infarction of 3%. From the clinical history, examination and electrocardiogram in the emergency room, independent predictors of death and death or any severe complication were determined by logistic regression analysis. These included age, initial degree of suspicion of infarction, electrocardiographic pattern, history of diabetes mellitus, history of congestive heart failure and on admission arrhythmias, loss of consciousness, acute congestive heart failure, or unspecific symptoms. From these analyses the probability of death or death or any severe complication can be calculated. Thus, 18% of patients hospitalized due to suspected acute myocardial infarction suffered a severe complication or died in hospital. From a statistical model it is possible to predict the in-hospital prognosis of every such patient.