A study was carried out in metropolitan Baltimore in which the short- and long-term prognosis of 655 patients with anterior myocardial infarction (MI) was compared with that of 520 patients with inferior/posterior MI. The study was performed on a community-wide basis in two time periods before the clinical introduction and widespread use of beta-blockade therapy. After simultaneous adjustment for several socio-demographic and clinical variables, the in-hospital case fatality rate was greater for patients with anterior (27.5%) than for those with inferior/posterior MI (22.9%) (p less than 0.05). Similarly, for those discharged alive from the hospital and followed up for as long as 10 years, patients with infarction of the anterior wall had a significantly poorer long-term survival than that of patients with infarction of the inferior/posterior wall (p less than 0.05). These results suggest that closer surveillance should be directed at patients with anterior myocardial infarction, both during the acute phase and after hospital discharge.