The authors analyse the results of studying intracranial (subdural) pressure during and after glymarite (a solution of glycerin and mannitol) injection in patients who were subjected to operations for intracranial hematomas and aneurysms of the brain. Forty patients were examined. It was found that the features of the intracranial pressure dynamics were determined by the initial pressure values and by the type of the pathologic condition. The hypotensive effect of glymarite was obvious and was manifested from the 8-10th minute after the beginning of the injection. Maximum reduction of the pressure occurred approximately one hour after the injection and was 20-60% of the initial value.