The objective of the present work was to study the pathological changes in various organs and tanatogenesis associated with Mallory—Weiss syndrome making use of the forensic medical and clinical materials. It was shown that the main cause of unrestrained vomiting resulting from alcoholic intoxication and leading to perfusive bleeding is not only the direct action of ethanol and surrogate alcohol on gastroesophageal mucosa and induced thrombocytopenia. Another cause may be brain oedema with subsequent cerebral herniation and irritation of the pseudobulbar centres responsible for the initiation of the vomiting reflex. The authors propose recommendations for forensic medical diagnostics of the cases of such hemorrhage.