•Group interventions based on life story work with adolescents in care are feasible.•Confidentiality and voluntariness are important aspects of the framework.•Mechanisms include normalization, mutual support, and exchange of experiences.•Effects include enhanced self-esteem, self-efficacy, openness, and relationships. Adolescents in out-of-home care are a high-risk population due to their accumulation of adverse childhood experiences. Furthermore, out-of-home placement itself is a critical life event. Life story work (LSW) is a method for coping with critical life events. However, the need for a high amount of resources makes its implementation in care settings difficult. To improve the accessibility of LSW in residential care, the ANKOMMEN (English “Arriving”) intervention was developed as a manualized and cost-efficient group intervention. This study aims to explore the experiences of adolescents who took part in the intervention in order to examine how participation benefited them and what contributed to these beneficial effects. For this reason, we analyzed n = 48 individual interviews with adolescents after completing the intervention. The focused interview analysis method was used to transcribe and code the interviews. The qualitative analyses revealed that the framework of the intervention helped the participants to open up and to process parts of their history within the group. Moreover, the group setting was a major contributory factor to the positive effects of the intervention by encouraging the participants to exchange their experiences, through mutual peer support and the normalization of adverse thoughts and feelings. Furthermore, participation in the intervention increased self-esteem and self-efficacy in some participants. It contributed to the improvement of positive relationships, helped clarify placement associated events, thoughts and feelings, and improved the acceptance of the placement. Further research is needed to validate these findings and thus widen the range of application of LSW.