A 70-year-old female retired high school teacher presented with complaints of a sensation of her teeth melting and swelling in her gums. At 68 years of age, she consulted a dentist due to the feeling of incongruity in her oral cavity. Although her oral discomfort transiently improved after the oral care instructed by the dentist, the symptoms soon relapsed and persisted. She was diagnosed with major depression at an outpatient’s clinic, treated with paroxetine (20 mg/day), and referred to our university hospital. Her psychiatric symptoms included oral cenesthopathy, depressed mood, persecutory delusion, auditory hallucination, and impaired attention and concentration. Her diagnosis was changed to late-onset schizophrenia, and she was treated with aripiprazole (24 mg/day) and paroxetine (20 mg/day). Her psychiatric symptoms were relieved. Six months later, she again presented with oral cenesthopathy accompanied by persecutory delusion, depressed mood, attention deficits, and anxiety. Aripiprazole was tapered off, and perospirone was gradually increased to 36 mg/day. She then presented with parkinsonism, including finger tremor, muscle rigidity at the upper and lower limbs, bradykinesia, hypersalivation, postural instability, orthostatic hypotension, constipation, and polyuria. Subsequently, she demonstrated rapid eye movement sleep behavior disorder. We reconsidered her diagnosis, and suspected DLB. She retained independence for basic activities of daily living and had no trouble remembering remote past life events; memory problems were restricted to recent events. Her Mini-Mental State Examination score was 27. Magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT), MIBG scintigraphy, and DAT scans were performed. The atrophy of medial central lobe was not pronounced in MRI (Fig. 1). MIBG scintigraphy showed a hypo-accumulation pattern (Fig. 2). Reduced uptake at the lateral basal ganglia was revealed in the DAT scan (Fig. 3). These findings supported the diagnosis of DLB. Perospirone and paroxetine were tapered off, and donepezil was started and increased to 5 mg/day. Four weeks later, the oral cenesthopathy, persecutory delusion, depressed mood, and cognitive flexibility were reduced; parkinsonism, however, persisted. Levodopa (75 mg/day) was added to the ongoing donepezil (5 mg/day), and her parkinsonism improved. Written informed consent was obtained from the patient for publication of this case report.