Background: Critical care nurses (CCNs) need to comply with caring behaviors when caring for postoperative cardiac patients. Furthermore, patient satisfaction is a key indicator of nursing care quality. As such, this study focused on these critical issues considering the limited research available on the impact of caring behaviors on postoperative cardiac patient satisfaction. Aim: To evaluate the impact of implementing a nurse caring behavior (NCB) protocol on postoperative cardiac patient satisfaction. Design: A randomized controlled trial with two parallel groups design was followed. Setting: The study was conducted at a cardiac surgery intensive care unit in the