The effect of osmotic diuretics (mannite and glimarite, 29 studies), colloid-osmotic diuretic (algurin, 22 studies), and saluretic (lasix, 58 studies) on intracranial pressure (ICP) was studied in 30 patients in the acute period of severe craniocerebral injury. It was found that the hypotensive effect of the diuretics depended on the state of the water-electrolyte homeostasis, the time of medication with the agents, the severity of the patient's condition, and the initial ICP. The effect of osmotic diuretics was highest in normoosmia and normonatriemia in ICP of 20-45 mm Hg. Medication with osmotic diuretics and algurin in the first 2-3 days after the injury as usually attended by the "yield phenomenon"; the hypotensive effect of algurin in this period was less manifest. The effect of lasix was higher in hyperosmia caused by hypernatriemia but lower in patients who were in a terminal and extremely severe state.