Background Chest compressions applied manually or with mechanical devices can encounter various types of injuries. The aim of this study is to analyse the corelation between the way the chest compressions were applied and the types of injury in deceased patients who underwent CPR for sudden cardiac arrest of non-traumatic aetiology. Study is reported as per STROBE guidelines. Methods This is a retrospective observational cohort study from two geographical regions of the Czech Republic. Adult patients (>18 years old) with sudden cardiac arrest of non-trauma aetiology resuscitated by the emergency medical services were included. The cohorts were divided based on the way the chest compressions were provided – manual compressions, compressions provided by mechanical device, and compressions provided manually with the use of cardio pump. The variables used were injuries found during the autopsy. Results The research set of 113 cases of non-traumatic adult sudden cardiac arrests consisted of 75 men and 38 women. Average time of resuscitation was reported as 32.9 minutes. Manual chest compressions were performed in 46 (40.35%) cases, manual chest compressions using cardio pump in 27 (23.68%) cases, and mechanical chest compressions in 40 (35.08%) cases. Conclusions The use of cardio pump or mechanical chest compressions relates to more left side serial rib fractures and skin injuries, than manual chest compressions in the group of deceased adults who underwent resuscitation of non-trauma origin.