Abstract. This paper examines the application of virtual reality cues, generating the biofeedback effects of a real tiled floor, reported in [8], for gait improvement in Parkinson's Disease (PD) patients. A portable apparatus, comprising head and body-mounted 3-axis accelerometers, a wearable computer and see-through head-mounted display, creates a virtual tiled floor, responding to the patient's own dynamics. Performance of PD patients using the device improved (higher speed, longer stride) by about 30% on average. Key words. movement disorders, Parkinson's disease, virtual reality