Pediatric overweight and obesity, a highly prevalent condition posing risks extending into adulthood, is considered a major public health concern. Findings from the pediatric obesity treatment literature support the efficacy of parental involvement across multiple formats. Family-based treatment is an outpatient intervention for adolescents with eating disorders that enlists parents as the primary agents of symptom management during the acute stages of illness, titrating down their involvement as severity of the disorder decreases. We adapted family-based treatment for pediatric obesity, modifying the original model to recognize that children and adolescents with obesity do not exhibit the developmental regression seen in eating disorders and to reflect the non-psychiatric nature of obesity. Thus, family-based treatment for pediatric obesity modulates the degree of parental involvement as a function of chronological developmental stage, not severity of the condition. To illustrate the implementation of this treatment, we present a case report of a 15-year old with an eight-year history of overweight and a greater than 30-pound weight gain prior to treatment. Through this case study, the three phases of family-based treatment for pediatric obesity and six-month post treatment follow-up results are presented through the lens of response from this adolescent and her family. We present this case report to illustrate the implementation of the intervention's adolescent module, and the potential impact of the approach in the treatment of adolescents with obesity and their families.