Background While adolescents are an at-risk group that is in a process of developmental crisis and requires guidance for adjustment. They may be traumatized by challenging conditions due to the negative experiences they are socially exposed to. Having to work is one of the most important social problems that increases the risk situation of this group. Roy's Adaptation Model is also quite suitable for use in interventions and research addressing developmental groups. It is believed that the adaptation of the individual to a new situation in their life contributes to their capacity to improve their health and increase their quality of life. Objective This study was conducted to determine the effects of a Health Education Program based on Roy's Adaptation Model on the healthy lifestyle behaviors and self-esteem levels of working adolescents. Design This study was designed as a randomized controlled trial. Method The study was conducted at a vocational training center in Turkey between March 14 and June 13, 2022. The sample consisted of 66 adolescents aged 14-18 years (intervention: 30; control: 36) trained at the Vocational Apprenticeship and Training Center. The adolescents in the intervention group participated in an 8-session program for 4 weeks. Data were collected using a Personal Information Form, the Healthy Lifestyle Behaviors Scale II, and the Rosenberg Self-Esteem Scale (RSE). Data collection took place before the program started, immediately after its completion, and 3 months later. This document was prepared in accordance with the Preferred Reporting Items for Analyses of Randomized Controlled Trials (CONSORT) guidelines. Results A significant difference was found between the intervention and control groups in favor of the intervention group in terms of their Healthy Lifestyle Behaviors Scale II scores in the 2nd measurement and their RSE score in the 3rd measurement. Conclusion The Health Education Program based on Roy's Adaptation Model is effective in increasing the healthy lifestyle behaviors and self-esteem of working adolescents. Patient or Public Contribution No patient or public contribution. Impact Roy's Adaptation Model can provide a conceptual framework for holistic studies to promote health for developmental groups.