Aim. The aim of the study was to carry out the biochemical analysis of vitreous humor for the development of the methods of postmortal differential diagnosis of diabetes mellitus comas. Materials and methods. In the vitreous humor of 378 patients suffering in the life time from diabetes mellitus, the following indices were determined: glucose, lactate, ketone bodies, «average molecular weight» peptides content. Results. Vitreous humor glucose content higher than 17 mmol/l proves hyperglycemic coma; at the same time, glucose content higher than 9,0 mmol/l and lower than 17 mmol/l is typical for precomatose status. In case of ketoacidotic coma, vitreous humor ketonic content is higher than 4,0 mmol/l, but in case of hyperosmolar ketoacidotic coma (hyperglycemia + ketoacidosis) ketonic bodies content is higher than 2,5 mmol/l and glucose content exceeds 7,0 mmol/l. Absence of glucose and vitreous humor lactate content lower than 10 mmol/l testifies the presence of hypoglycemic coma. Conclusions. The methods for postmortal differential diagnosis of diabetic comas and endogenous intoxication syndrome were developed.