Herein, we present five cases with frontotemporal dementia whose behavioral symptoms were improved by Yokukansan, a traditional Japanese medicine (Kampo). All five patients were prescribed Yokukansan (7.5 g/day) to reduce their symptoms. The patients' symptoms were evaluated comprehensively using the Neuropsychiatric Inventory (NPI) and the Stereotypy Rating Inventory (SRI) before and 4 weeks after Yokukansan treatment. The mean (± SD) scores on the NPI and the SRI before treatment were 55.6 ± 5.4 and 22.2 ± 6.5, respectively. After treatment, these scores were 30.0 ± 7.8 and 11.6 ± 7.5, respectively. Yokukansan was effective for the treatment of clinical symptoms in all five patients without adverse effects and significant changes in laboratory data. Although antipsychotic drugs have been used to control behavioral symptoms, their associated adverse effects frequently impact on the activities of daily living and quality of life of treated patients. The present cases suggest significant improvement of behavioral symptoms in frontotemporal dementia with Yokukansan treatment, leading to probable benefit of the use of Yokukansan in individuals with frontotemporal dementia.