Background: Cardiopulmonary Resuscitation (CPR) is an emergency procedure for the return of spontaneous circulation in patients with cardiac arrest. Many factors can affect the success of CPR. Objective: This study aims to investigate the success rate of CPR and its related factors in patients referred to Dr. Heshmat Hospital in Rasht, Iran. Methods: In this retrospective cohort study, participants were 1008 patients who had underwent CPR in Dr. Heshmat Hospital in Rasht, Iran. Data were collected from April 2016 to March 2019 using the Utstein style standard form, which assesses related factors and the times related to CPR. The association between CPR outcome and demographic/clinical factors was examined using independent samples t-test, chi-square test, and multiple logistic regression analysis. Results: The CPR success rate was 34.8%. The CPR success rate was higher in patients with no asystole rhythm, short CPR duration, and in-hospital cardiac arrest. Compared to patients in CCU ward, those received CPR in other wards (except ICU) were more likely to have successful CPR. Furthermore, in patients with in-hospital cardiac arrest, the odds of successful CPR decreased with the increase of age. Conclusion: Since patients with asystole rhythm had the lowest success rate of CPR and this rhythm occurs due to delay in initiation of treatment at the end of cardiac arrest, early treatment of patients with cardiac arrest caused by ventricular tachycardia or ventricular fibrillation can increase the chances of a successful CPR.