Objective: This study aimed to determine the effect of family support program on the anxiety, depression, stress, and satisfaction of the family caregivers of patients with open heart surgery. Samples: Ninety family caregivers of the patients undergoing open heart surgery in FATEMEH- ZAHRA Hospital, Sari, Iran recruited in the study. Inclusion criteria: Family member should have a key role in the patient’s care, have the ability to read and understand Persian, be at least18 years old, not have a history of taking care of a cardiac surgical patient, not be a member of the healthcare team, and finally the patient shouldn’t be the candidate of emergency surgery. Exclusion criteria: Occurrence of any postoperative complications such as bleeding, reoperation, etc.; the patient is extubated in the first 24 hours after surgery, the patient or her/his family members cannot participate in all instructional sessions. Intervention: In this experimental clinical trial, the participants will be divided into experimental and control groups. In the experimental group, family caregivers receive information support ,instructional sessions and booklets, phone calls along with emotional support. On the other hand the control group receives the routine hospital support. Anxiety, depression, and stress levels were measured by DASS21 questionnaire and Satisfaction measured with satisfaction of the family members of patients in Intensive Care Units questionnaire