The influence of piracetam on the level of inorganic and phospholipid phosphorus in blood of ischemic stroke patients was evaluated. In healthy patients piracetam (2G, i.v.) diminished the concentration of inorganic phosphorus and essentially lowered the content of ion connected with phospholipids. In stroke patients inorganic phosphorus was primarily enhanced and organic lowered. Treatment with piracetam lowered the concentration of both inorganic and phospholipid phosphorus in blood.