Motor disturbances in 16 patients with normal-pressure hydrocephalus were assessed by quantitative registration of handwriting, fine movements of the hand, hand tremor, postural instability, and gait. Tremor intensity was measured using an accelerometer and electronic integration of the accelerometer curves. Postural instability was measured on a computer-assisted force-plate, and computerized analysis of gait was made using an instrumented treadmill. Severe disturbances in motor performance in the upper extremities and postural stability were found. The gait of the hydrocephalic patients was characterized by a very low speed, short steps, ataxia (especially in the vertical direction), and high energy consumption. After shunt operation, significant improvement was found in motor performance in the upper extremities and postural stability, and gait ataxia decreased in all patients to values within the 95% confidence interval of age-matched controls.