OBJECTIVE: To provide a theoretical study and model for the bioethical foundations of the factors that influence adolescents' healthcare decisional capacity. SOURCES: Materials from diverse sources, including indexed articles in recognized databases and official government documents, were examined for a purposefully selected sample. The research consisted of two stages: selection of documents and reflective thematic analysis, followed by the preparation of a report. The analysis adopted a phenomenological stance and a reflective view compatible with human rights. To reduce bias and ensure the robustness of the results, measures such as data triangulation were employed. Ethical measures were taken to ensure data integrity, including considerations of anonymity and conflicts of interest in the selected studies. SUMMARY OF THE FINDINGS: It was possible to list intrinsic and extrinsic factors of the adolescent patient that influence their decisional capacity regarding health. A theoretical model was developed to discuss these factors for evaluation by means of an infographic. CONCLUSIONS: It seems clear that the evaluation of healthcare decisional capacity of adolescents must position itself ethically regarding the tension between the moral duty to respect the self-determination of the able subject and the need to protect adolescents decidedly unable to make a specific health decision at a given time.