To test the effectiveness of an intervention delivered by health professionals outside the school environment to girls identified with issues such as poor body image, low self-esteem, low self-confidence, nonparticipation in sports, or being overweight or underweight. The study's design was a stepped-wedge randomized controlled trial to test the efficacy of an intervention on self-esteem, impairment induced by eating disorders, self-efficacy, body satisfaction, and dieting behaviors. The study took place at the community health center located in a culturally diverse area of Melbourne, Victoria, Australia. Participants were 122 primary and secondary school girls between 10 and 16 years of age. Girls on the Go! is a 10-week program designed to improve self-esteem, body image, and confidence, using an empowerment model that involved interactive and experiential learning approaches. Weekly themes included body image and self-esteem, safety and assertiveness, a healthy mind, physical activity, healthy eating, trust and confidence, and connections. Measurements were made using Rosenberg Self-Esteem Scale, clinical interview assessment, health self-efficacy (included mental health and physical health self-efficacy scales), body esteem scale, and the Dutch Eating Behavior Questionnaire for Children. A linear mixed model was used. The intervention led to a significant increase (p < .05) in self-esteem and self-efficacy (mental and physical health self-efficacy subscales), for both primary and secondary school-aged participants and reduced dieting behaviors (secondary school participants). These gains were retained after 6 months of follow-up. This group-based, low-dose intervention, which, although targeting girls with a range of psychological issues and including both overweight and underweight participants, is a successful means of improving self-esteem among girls from diverse cultural backgrounds.