Interpersonal emotion regulation is important for developing and maintaining coworker relationships. Understanding what motivates this form of emotion regulation can provide insight into how interpersonal relationships influence personal and organizational outcomes. Using experimental vignettes, this thesis sought to: 1) contrast motivational tendencies for interpersonal emotion regulation (e.g., instrumental and prosocial motives), 2) examine relations between gender, emotional intelligence and interpersonal emotion regulation, and 3) explore additional motives for regulating others’ emotions. Findings suggest that between coworkers, prosocial and instrumental considerations underlie decisions to engage in interpersonal emotion regulation, with instrumental motives being stronger than prosocial motives. Moreover, emotional intelligence was found to predict the use of effective interpersonal emotion regulation strategies. An exploratory qualitative analysis suggests the existence of additional motives for interpersonal emotion regulation (e.g., identity-preserving motives and personal beliefs motives). Collectively, these findings demonstrate the operation of motives in regulating the emotions of others in the workplace.