Research suggests that people deliberately try to improve others’ feelings in a variety of social contexts. However, little is known about whether and how interpersonal affect regulation influences the quality of people’s relationships. Two applied social network studies investigated the relational effects of interpersonal affect regulation. In Study 1 attempts to improve others’ affect among grocery store employees were associated with both regulatory targets’ and agents’ perceptions of friendship and trust. In Study 2 we replicated this finding among staff and prisoners in a high-security prison. Additionally, we showed that these associations were mediated by positive changes to regulatory targets’ and agents’ affect. The results provide insights into the social consequences of interpersonal affect regulation and help to elucidate the factors influencing the formation and maintenance of high-quality relationships.