Introduction: Organizational commitment is manifested in the forms of taking pride in organization, enhanced motivation for engaging in organizational duties, staying at organization for a longer time and knowing organization as a valuable organization. So decreased organizational commitment among medical staff led researchers to investigate the organizational commitment of CCUs in Mazandaran Heart Center. Methods: This is a descriptive-analytical study carried out in teaching hospitals of Mazandaran University of Medical Sciences, Heart Center. Allen and Meyer's organizational commitment questionnaire was used to collect data from 90 nurses selected by census from CCU nurses. Data was analyzed using SPSS 21. Results: Of studied cases, 19 (18.9%) were male and 73 (81.1%) were female with a mean age of 7.25±34.4. Among age, job experience and work hour variables, only age and job experience were considered to be significant. Conclusions: Supervisors and managers should promote nurses' organizational commitment through giving facilities and rewards.