This study aims to describe the competencies of Certified Nurse Specialists in Critical Care Nursing （CCNSs） in supporting nurses who have difficulties with surrogate decision-making. Semi-structured interviews of eight CCNSs were conducted and the obtained data were qualitatively analyzed. The results showed that CCNSs perceived a need to support both the nurses’ dilemmas and family support in surrogate decision-making. CCNSs may support the difficulties based on education by these roles. “To become a model by performing the information collection and mental care of the family instead of the nurse”: practice. “To clarify problems from information and consider care strategies together”, “to give feedback and following over respecting the subjectivity of nurses”: consultation. “To make opportunities to share ideas and care strategies among nurses”, “to advocate nurse in medical team”: coordination. The need for problem-solving, educational, and coordination competency for this support has been suggested.