Many patients with acoustic neuroma experience hearing loss, tinnitus, and equilibrium disturbance. Gait studies performed using tactile sensors placed under the feet have indicated that an acoustic neuroma causes unstable gait, even though this cannot be detected by visual observation. Three-dimensional motion analysis is a useful tool to assess gait. The purpose of this study was to use a three-dimensional motion analysis system to quantify the spatiotemporal and kinematic parameters of gait in patients with acoustic neuroma. Seventeen patients with unilateral acoustic neuroma and seven age-, height-, and foot-sizematched healthy subjects participated. Subjects were asked to walk 4 meters in eyes-open and eyes-closed conditions. Gait speed, stride length, stride duration, head movements in the vertical direction and yaw, pitch, and roll dimensions, gait deviation, forefoot motion, and ankle plantar flexion angle at heel strike were quantified. Patients with acoustic neuroma had slower gait with wider step width and shorter stride length along with greater head movement in pitch and roll than controls. In addition, patients with acoustic neuroma had lower ankle plantar flexion angle at heel strike than controls, especially in the eyes-closed condition. These characteristics of gait increase our understanding of the pathophysiological changes caused by acoustic neuroma.