Background: The development of prosocial competencies in university students can be attained through the implementation of Service-Learning (S-L) methodology by carrying out a community service to groups of foreign unaccompanied minors (FUM). Physical Education Teacher Education (PETE) and Sport Science (SS) students involved in an S-L experience normally develop a critical way of thinking as they face social conflicts. Besides, social justice education and S-L attempt to help in favour of social inclusion of vulnerable groups. Purpose: This study aims to assess the development of prosocial competencies in PETE and SS students taking a Dual Degree Program in Physical Activity (PA) and SS and Primary Education. This is done through S-L methodology, by carrying out a community service to groups of FUM. Method: A total of 21 male and 9 female PETE and SS students participated in this study. The methodology used is of a qualitative nature. Reflective diary is used as an instrument for data collection, and content analysis as an information analysis technique. Results: It has been observed an improvement in the prosocial competencies of the PETE and SS students involved in the S-L experience. The competencies with the greatest number of references and, therefore, those with a greater presence in their testimonies, include organisation, proactivity and optimism, self-esteem, and tolerance and respect. Conclusion: The S-L is capable of undertaking a transformative role which enables PETE and SS students to acquire prosocial competencies in contexts relating to cultural diversity and social justice.