Factors contributing to the sex difference of in-hospital mortality after acute myocardial infarction (MI) are still unknown. We compared the clinical characteristics on admission and in-hospital outcome of consecutive 1,354 patients with acute MI between the 2 sexes. Age on admission was about 7 years older in women than in men. In-hospital death was significantly more frequent in women. Pulmonary congestion and hypertension were more likely in women with higher serum levels of total cholesterol and LDL cholesterol. A higher prevalence of current smoking and inferior wall involvement and lower serum HDL cholesterol level were observed in man. After adjusting for age, adverse in-hospital mortality for women was observed in both younger and older patients. Multivariate logistic regression analysis demonstrated that age, location of infarction, recanalization and serum C-reactive protein (CRP) concentration were independent predictors for in-hospital mortality for overall patients, while age and recanalization were independent predictors for male gender, and pulmonary congestion and serum CRP concentration were independent predictors for female gender. In-hospital outcome after acute MI was worse in women. A multivariate logistic regression model revealed that the sexually different factors affected in-hospital mortality in females