The authors propose that gender-differentiated patterns of jealousy in response to sexual and emotional infidelity are engendered by the differential impact of each event on self-esteem for men and women. Study 1 demonstrated that men derive relatively more self-esteem from their sexlives, whereas women’s self-esteem is more contingent on romantic commitment. Based on terror management theory, it is predicted that if gender-differentiated responses to infidelity are motivated by gender-specific contingencies for self-esteem, they should be intensified following reminders of mortality. In Study 2, mortality salience (MS) increased distress in response to sexual infidelity for men and emotional infidelity for women. Study 3 demonstrated that following MS, men who place high value on sexin romantic relationships exhibited greater distress in response to sexual infidelity, but low-ex-value men’s distress was attenuated. The authors discuss the implications for evolutionary and self-esteem-based accounts of jealousy as well as possible integration of these perspectives.