Thirteen different motor and balance functions were examined in 76 patients age 65 +/- 13 (mean +/- SD) years with normal pressure hydrocephalus (NPH) before and 3 months after a ventriculoperitoneal shunt operation. Preoperatively, the tests were performed before and after lumbar tap of 50 cc cerebrospinal fluid. The patients showed significant improvement in all thirteen functions at the 3-month examination. The improvement was approximately 25% in all the motor functions, except for balance, in which the improvement was even more striking. Different etiological subgroups of NPH patients, including the idiopathic form, exhibited the same degree of improvement. The improvement after the lumbar tap was significant in all functions except one-legged stance, and amounted to approximately 30% of the improvement seen after the shunt operation. Our results clearly show that the impairment in motor functions in NHP patients is general, involving many motor activities performed in daily life, and is not restricted solely to the gait.