Peer mentoring has shown beneficial effects in facilitating academic and social integration among first-year students in higher education. Previous research is, however, limited by the exclusion of a comparison group, to examine whether the integration process still occurs among non-mentored students, independently of peer mentoring. By using Tinto´s theoretical framework, we examine the effects of a formal peer mentoring program, comparing these effects on integration with non-mentored students. Data was gathered from focus group interviews and analyzed using thematic analysis. Our findings show that peer mentoring supports the integration process among first-year students, although the results suggest that it is not a necessary condition to ensure that integration occurs. Future studies should further extend the research to also include an evaluation of other activities taking place at the institution, to expand the knowledge of which measures facilitates the integration process.