Patients with Parkinson’s disease (PD) have various types of gait disturbance that are thought to result from impairments in motor timing. Gait disturbances are markedly improved with the use of appropriate visual and auditory cues. In this study, patients suffering from mild to moderate PD underwent a structured music therapy session in which they were trained to walk while mentally singing. The patients were trained in 7 progressive tasks, with a final goal of walking while mentally singing. Before and after the training session, they were videotaped. The video was analyzed for time and steps while walking straight paths and while turning. After a single session of training, the time and steps were significantly improved in both situations. Follow-up interviews with the patients indicated that they effectively utilized mental singing while walking in their daily lives. We propose that singing regulates basal ganglia function and allows patients with PD to keep time regularly. The task used in the present study was simple, required no special tools, and could be utilized anytime and anyplace. Thus, walking while mentally singing has potential for improving the gait of individuals with PD.