This study examined the relation between self-esteem and responses to a romantic partner's moods. College students in dating relationships imagined one scenario in which their romantic partners were in a positive mood and one in which their partners were in a negative mood. A probable source of each mood was suggested to half the participants. Participants reported their cognitive, affective, behavioral, and attributional responses to each scenario. When the partner's mood was negative and ambiguous in cause, participants with low self-esteem felt more responsible for the mood, more rejected, and more hostile than did those with high self-esteem. A mediational analysis suggested a dependency regulation explanation of the results, such that low self-esteem people perceived self-directed negativity in their partners' bad moods and in turn responded with more negativity toward their partners.