Being overweight is regarded as the most common nutritional disorder of children and adolescents in the United States. The escalating problem of being overweight or being obese in our society indicates the need for treatment strategies that encompass an all-inclusive approach. Moreover, these strategies need to be comprehensively evaluated for their effectiveness. Nurses are in an excellent position to ensure that this occurs. The purpose of this study was to determine whether using a mixed-methods approach was an efficacious way to provide a comprehensive evaluation of the behavior modification benefits of a weight loss/weight management nursing intervention in African-American adolescent girls (13-17 years of age). The overall effectiveness of the intervention was evaluated by analyzing pre- and post-program measures of weight, body mass index, cholesterol, blood pressure, self-esteem, depression, and body image (quantitative data); conducting focus groups with mothers of the participants; and administering open-ended, written questionnaires to the participants (qualitative data). Findings from the quantitative data indicated favorable outcomes in weight, blood pressure, cholesterol, body mass index, self-esteem, and body image, indicating that progress had been made over the course of the program. Furthermore, qualitative data indicated that mothers of the participants observed positive behavioral changes related to eating and exercise patterns and participants demonstrated perception of these changes as well.