To assess differences between male and female recipients after heart transplantation, we retrospectively reviewed 140 consecutive heart transplant recipients (119 males and 21 females) with regard to sex and characteristics before and after transplantation. Before transplantation, fewer female recipients had heart failure on the basis of coronary artery disease (14% versus 56%, p = 0.001), and more females required inotropic agents (71% versus 38%, p = 0.007). Although average follow-up (for females 430 +/- 73 days, range 12 to 1097 days; for males 412 +/- 27 days, range 1 day to 1103 days, mean +/- standard error of the mean), mortality (one female and nine males), and proportion of recipients with infectious complications (48% females and 52% males) did not differ between the groups, female recipients manifested a higher incidence of rejection during the first 4 months (2.39 +/- 0.27 episodes versus 1.67 +/- 0.11 episodes, p = 0.010) and during follow-up (3.24 +/- 0.44 episodes versus 2.20 +/- 0.21 episodes, p = 0.012). Although it was possible to discontinue maintenance dosages of corticosteroids in 65% of males, corticosteroid discontinuation was possible in only 17% of females (p less than 0.001). Furthermore, in a stepwise logistic regression analysis that included age, crossmatch (no female recipients with positive results, three males with positive results), cause of heart failure, and hemodynamic status before transplantation, females were more likely to experience a rejection episode than males (p less than 0.001). Although female recipients experience rejection episodes more than their male counterparts after heart transplantation and are more likely to require maintenance corticosteroid therapy, survival and the incidence of infectious complications are not different.