Plasma phospholipids were examined in patients with delirium tremens in the acute phase of the disease and after recovery. The levels of lysolecithin, phosphatidylinositol, phosphatidylethanolamine, sphingomyelin and the total of phospholipids were decreased in comparison to normals. Phosphatidylethanolamine, phosphatidylinositol and the total phospholipids were diminished in comparison to patients with liver cirrhoses. Only in the plasma of patients with liver cirrhoses with bad prognosis (hepatic coma) similar low levels of total phospholipids were found. It is concluded from these results, that the synthesis of phospholipids is reduced during delirium tremens.