Introduction: A life-threatening illness can cause the involvement of family members and the imposition of psychological and physical stress on them. Certainly, the family is a very valuable resource in patient care and plays an important role in maintaining the emotional support and patient’s recovery. The aim of this study was to explain the family members’ supporting behaviors of the patient admitted to the cardiac special units. Methods: This qualitative study was performed in the cardiac special units in Isfahan. The number of participants was 20, including 5 nurses, 8 family members, and 7 patients. The data were collected through interview and observation by purposive sampling. Then, the data were analyzed by Graneheim and Lundman’s qualitative content analysis method. The study lasted 12 months. Results: Data analysis showed that family’s support can be classified into three levels, including support by the therapeutic alliance (attempts to console and reassure, restoration of selfesteem, diminishing patient’s insensitivity, commitment to the patient, and visiting the patient ), participatory information (obtaining reliable information from the nurse, active role in providing meaningful information about the patient’s prognosis), practical and instrumental support (searching for economic support resources, providing the patient with the necessary equipment, trying to do the right care taking into account the family culture). Conclusion: Understanding family’s supportive behaviors can help improve counseling and planning for quality care of patients admitted to the cardiac care units (CCUs).