Background and Aims: Nurses should have cardiopulmonary resuscitation (CPR) knowledge and skills to be able to implement effective interventions during in-hospital cardiac arrest. The aim of this descriptive study was to assess mortality impact after nurses' CPR training with pre-CPR training data at our institute. Methods: Training regarding CPR was given to nurses, and CPR mortality 1-year before basic life support (BLS) and advanced cardiac life support (ACLS) training were collected and compared with post-training 1-year CPR mortality. Results: A total of 632 adult patients suffering in-hospital cardiac arrest over the study period. CPR was attempted in 294 patients during the pre-BLS/ACLS training period and in 338 patients in the post-BLS/ACLS training period. In the pre-BLS/ACLS training period, 58 patients (19.7%) had return of spontaneous circulation (ROSC), while during the post-BLS/ACLS training period, 102 patients (30.1%) had ROSC (P = 0.003). Sixteen of the 58 patients (27.5%) who achieved ROSC during the pre-BLS/ACLS training period survived to hospital discharge, compared 54 out of 102 patients (52.9%) in the post-BLS/ACLS training period (P < 0.0001). There was no significant association between either the age or sex with the outcomes in the study. Conclusion: Training nurses in cardiopulmonary resuscitation resulted in a significant improvement in survival to hospital discharge after in-hospital cardiac arrest.