Abstract: Shock secondary to closed head injuries alone is unusual, and other causes must be excluded before assuming brain injury to be the cause. The successful management of injuried patients requires a working knowledge of the pathology of shock. Four hundred and twenty two patients with sereve closed head injury were admitted from January, 1972 to December, 1981. In 248 cases （58.7%） shock was present, and only 17（4%） of the patients belong to the shock secondary to head injuries alone. Thus, if shock is present, a seach must be made for its cause. Ruptured intra-abdominal organs or chest trauma may be present, or a loss of sympathetic tone from spinal cord injuries may occur: all these conditions may produce shock. Rarely, serious hemorrhage may occur from the extensive scalp lacerations and lead to hemorrhagic shock.