The results of quantitative determination of the myoglobin (MG) levels in the cadaveric blood are presented. The blood samples were collected from the subjects who were affected by or died from various diseases. Modern forensic medical practice requires the use of new methods for the study and diagnostics of intravital traumatic damage and elucidation of the concrete cause of death enabling the law-enforcement agencies to rapidly and effectively investigate the offences against the person. A total of 161 cases were analysed. The myoglobin levels were shown to be highly variable among the casualties. They were less dependent on the concrete form of injury or disease and were in the first time related to the rate at which death approaches and the state of blood circulation. The MG level was shown to drop appreciably in the case of sudden cardiac arrest whereas a prolonged agonal period was associated with its significant increase.