Summary: A number of studies have addressed outdoor and adventure programs over the past 50 years. Despite empirical evidence that demonstrates the personal benefits of group interventions, research investigating the mechanisms responsible for these effects is scarce. This is particularly so for groups in natural outdoor and adventure settings. There is therefore a need to improve our understanding of the processes involved. This research focused on personal and interpersonal processes that occurred during an outdoor group expedition. Semi-structured interviews were undertaken with 23 subjects aged between 17 and 21 who had participated in an 18-day expedition. The data are examined through a theoretical framework known as “helping factors” often used when studying benefits of a group intervention. Findings: The results show that participation in the program promoted selfunderstanding, interpersonal learning, socializing techniques, and cohesion. Altruism, imitative behavior, universality, and imparting information were also important. As for existential factors, corrective recapitulation of the family, catharsis, and hope, these were rarely mentioned if not absent. Applications: The results give a better understanding of the helping factors in such programs and of their potential role in the group process, as well as their application in social work practice.