Nurses play a key role in providing integrated supportive care to cancer patients for their various needs. Efforts should be made to identify the competencies required for nurses providing integrated supportive care to cancer survivors, evaluate the competence level with reliable and reasonable tools, and continuously improve them. In Phase 1, the items of the scale were developed through a literature review and by conducting a focus group interview. In Phase 2, the validity and reliability of the scale were analyzed. A total of 504 nurses participated. Data were analyzed using item analysis, exploratory factor analysis, confirmatory factor analysis, Pearson's correlation with other scales, internal consistency, and split-half reliability. The developed scale consisted of 22 items. These items were grouped into five subscales and labeled as professionalism enhancement, care coordination, comprehensive nursing needs assessment, providing tailored information and education, and recurrence surveillance and secondary cancer prevention. Confirmatory factor analysis supported good convergent and discriminant validities. The criterion validity was verified. The internal consistency of the scale measured by Cronbach's α was 0.91. The developed scale is expected to be used as an instrument to identify cancer survivor integrated supportive care competencies of nurses in practice.