The main goal of this qualitative research is to shed light on the protection and vulnerability factors in teenagers who are living in foster care and considered to be resilient. Twelve young people (6 boys and 6 girls), who were from 14 to 17 years old and who had been placed in homes because of behavioural problems, participated in this study. These young people, who had been in placements for an average of 5.6 years, were identified as being resilient based on a grid filled out by practitioners and on a clinical discussion. Two interviews were held with each teenager. The results point to environmental protection factors (significant relationships with adults, particularly practitioners, quality services, and sources of approval) as well as individual factors (will to succeed in life, perception of control, adaptation strategies) that fostered these young people’s resilience.