The causes of the high mortality of acute myocardial infarction in women as compared with men are controversial. The objective of this study is to assess the role of the therapeutic effort and socioeconomic factors on the genesis of this excess of mortality. We studied, using a retrospective cohort design, 491 men and 124 women admitted with the diagnosis of acute myocardial infarction. As a group, women were older (69 versus 61 years of age, p < 0.00001), showed a higher prevalence of cardiac failure on admission (44% versus 26%; p = 0.00008) and a higher mortality in the coronary care unit (29.3% versus 12.9%; p = 0.00002). In addition, the women showed an unfavorable socioeconomic profile and received a lower relative therapeutic effort, as assessed by the Therapeutic Intervention Scoring System. There was statistical interaction between gender and marital status, with a higher mortality in the unmarried male, comparable to that of women. Within the married group, the excess of mortality in women persisted after adjusting for age and Killip group (adjusted odds ratio = 2.48, 95% confidence interval between 1.26 and 4.89). None of the studied socioeconomic variables was independently associated to mortality, once age, Killip group and marital status were taken into account. After adjusting for therapeutic effort, the differences between men and women increased. Women admitted with acute myocardial infarction show a poor short-term prognosis that is not explained by their socioeconomic profile nor by the differences in therapeutic effort.