Liver cancer poses significant health challenges worldwide, particularly for ethnic minority populations, who often face barriers such as cultural differences, limited health literacy, and inadequate access to healthcare, contributing to poorer self-management and treatment outcomes. Existing self-management tools do not adequately address the unique needs of ethnic minority liver cancer patients, necessitating the development of a culturally tailored assessment scale.Grounded in the Health Belief Model, this study developed a self-management behavior assessment scale specifically for ethnic minority liver cancer patients. The scale was constructed using a comprehensive literature review, semi-structured qualitative interviews with 11 ethnic minority liver cancer patients, and two rounds of expert consultation via the Delphi method. The initial item pool was refined through expert input to ensure relevance and cultural sensitivity.Through literature review and semi-structured qualitative interviews with 11 ethnic minority liver cancer patients, four key dimensions were identified: health behavior management, disease perception and cognition, psychological and emotional regulation, and information acquisition and decision-making participation. These dimensions and items were further refined through two rounds of expert consultation using the Delphi method, ensuring the scale's cultural relevance and content validity. As a result, a self-management behavior assessment scale was developed, consisting of four dimensions and 31 items tailored to the specific needs of ethnic minority liver cancer patients.This newly developed scale provides a culturally sensitive tool to assess self-management behaviors in ethnic minority liver cancer patients. It has the potential to enhance patient care by identifying culturally specific barriers to effective self-management. Further research is needed to validate the scale's reliability and applicability in broader patient populations.© 2025. The Author(s).