With roots in experiential education and Outward Bound, wilderness therapy (WT) is a growing field of mental health care for youth. WT uses outdoor modalities combined with therapeutic interventions to assist youth to promote clinical changes. Previous research has shown it to be effective in improving the mental health of clients; however, little research has looked at the impact of WT on physical outcomes as well. This study examined changes in the body composition and mental health outcomes of adolescents participating in one WT program. On average, youth in the sample moved to a more healthy weight and body mass index (BMI) or were able to maintain at a healthy level. Youth also experienced significant improvements in their mental health functioning. Given the adolescent obesity crisis along with adolescent female challenges with body image, these results show that WT could be a promising intervention for youth struggling with these issues.