Relaxation is a coping mechanism that helps to regulate emotions and is associated with prosocial responses. This paper included two studies: 1) a randomized clinical trial conducted with 139 university students who participated in a relaxation program and were assessed on interpersonal relationships over time; 2) a correlational study that assessed the relationship between emotional regulation, cognitive functioning, the importance attributed to sociability, and interpersonal relationships. Results revealed that interpersonal relationships did not change over time due to the relaxation intervention. The importance attributed to sociability played a moderating role in the relationship between emotional regulations and interpersonal relationships. The results suggest the need for further studies and emphasises the critical role of emotional regulation skills in university students.