Relevance: closed chest injury is one of the most common types of injuries that can cause life-threatening conditions. Victims with such injuries often require carrying out a forensic medical examination. The purpose of this study is to determine from forensic medical aspects the severity of chest injuries in patients treated in a specialized surgical hospital in order to establish additional criteria for forensic diagnosis of such injuries. Materials and methods: 66 medical histories of patients with chest injuries who were treated at the V.T. Zaitsev Kharkiv Institute of General and Emergency Surgery. Results. A forensic medical assessment of the severity of chest closed injuries of the chest based on of clinical findings was performed. Morpho-clinical approach was used to determine the severity of injuries. Severe injuries were estimates in 22.7% of cases, mainly in the case of following acute respiratory failure. Moderate injuries were estimated in 77.3% of cases, mainly in injuries with rib fractures that caused no danger to life. It has been established that in the available scientific and methodological literature there are no diagnostic morpho-clinical signs for qualitative forensic assessment and prediction of the final results of closed chest injuries; moreover, there exist different views on forensic assessment. Conclusions: this study has determined that when using the morpho-clinical approach of forensic assessment, the additional diagnostic signs of closed chest injuries should be applied when assessing the severity of injuries including dynamics and duration of recovery from posttraumatic morpho-functional changes of injured organs, loss of a part or whole respiratory organ (lungs), the emergence of life-threatening conditions. The ways of further improvement of forensic diagnosis in the assessment of such injuries by the degree of their severity have been identified.