All patients with presumed coronary problems seen at the Chaim Sheba Medical Center during a one-year period were followed up. The fate of those who were not hospitalized and the factors contributing to the two types of erroneous decisions, ie, refusing hospitalization to those needing it and unnecessary hospitalization of others, were evaluated. Approximately 50% of the patients were not admitted. Myocardial infarctions were later diagnosed in 6% of these patients. Another 8% were eventually categorized as other cardiac emergencies. Ten percent of all patients subsequently diagnosed as having myocardial infarctions were not admitted. On the other hand, 56% of the patients whose cases were later not considered to have been emergencies were hospitalized unnecessarily. Previous hospitalization for cardiac disease played a major role in making an error of both types. Other factors influencing the physician's decision regarding the patients' disposition included their age, sex, ethnic origin, and the findings from the emergency room electrocardiogram.