In 641 patients (535 men and 106 women) with acute myocardial infarction (AMI), a mortality of 16.63% was recorded among the former and one of 42.45% among the latter. No significant difference was observed in the age groups up to 40 years, in the group from 41 to 55 years, and in those over 71; the difference between percentages (17.09 vs 38.23) was instead statistically significant (p less than 0.01) in patients in the age group from 56 to 70 years. This difference was significant (p less than 0.01 or 0.001) with regard to mortality in diabetics (21.36% vs 46.34%), nondiabetics (13.09% vs 30.36%), hypertensives (19.72% vs 37.70%) and nonhypertensives (12.86% vs 36.11%), as well as in patients with previous infarction (33.36% vs 81.82%) and in those with first infarction (12.18% vs 31.39%). Since this phenomenon does not seem related to any particular feature of infarction nor to a particular predisposition to specific causes of death, the reasons for such severe prognosis in women require clarification.