Interpersonal goals and adult attachment have implications for how people interact with others as well as for emotion experience and regulation. Literature on intrapersonal emotional processes has typically not examined motivations underlying people's engagement with others' emotions and its connections to individual differences related to close relationships such as attachment. This study analyzed the relationships between interpersonal emotion regulation motives, perceived social interaction outcomes, and attachment. Undergraduates (N = 211) reported their trait attachment. Experience sampling was used to examine the reasons why they wanted to regulate others' emotions during daily interactions and perceived changes in their own well-being and relationship quality with the target of regulation. Attachment anxiety was associated with more self-focused prohedonic motives and impression management motives, while attachment avoidance predicted less perceived increases in emotional and relational well-being after interactions. People who tended to report more (self- and other-focused) prohedonic and less impression management motives in daily life perceived more positive changes in their emotional well-being and people who tended to report higher emotional similarity motives perceived more positive changes in their relational well-being after interactions People also perceived more positive emotional and relational interaction outcomes at times when they held more (self- and other-focused) prohedonic, impression management, or relationship maintenance motives and less self-focused performance and relationship distancing motives. Overall, these findings suggest that attachment anxiety may guide why people engage with other people's emotions and these extrinsic interpersonal emotion regulation motives may play a role in socioemotional outcomes of daily interactions. (PsycInfo Database Record (c) 2023 APA, all rights reserved).