Content of so-called "middle mass molecules" in blood serum of patients with acute burn toxemia was studied by means of gel filtration on Sephadex G-25. Acute burn toxemia was accompanied by accumulation of the molecules in blood serum of the patients with burns; amount of these molecules correlated with a severity of burn trauma. The "middle mass molecules" were effectively eliminated after haemosorption on a charcoal sorbent SKN.2M. The rate of the "middle mass molecules" elimination in haemosorption correlated with improvement of the patients clinical state, with a decrease in symptoms of intoxication; manifestations of acute psychosis were also decreased.