The cerebellum is involved not only in the motor function but also in cognition and emotion. Therefore, impairment of the cerebellum is associated with cognitive deficits and affective symptoms in addition to motor deficits, which is known as cerebellar cognitive affective syndrome (CAAS). We herein report a case of psychomotor excitation caused by CAAS in which a multifaceted approach was effective.The patient was a 20-year-old woman. She had received surgery for cerebellar astrocytoma in her childhood. She experienced a problem with walking at 18 years of age following emergency surgery for obstructive hydrocephaly, an aftereffect of the surgery for astrocytoma. Since then, her walking problem worsened every time she received surgery for obstructive hydrocephaly, which seriously afflicted her. At 20 years of age, she had severe psychomotor excitation and self-harmed with suicidal ideation during hospitalization in the neurosurgery unit of Kumamoto University Hospital. She was moved to the neuropsychiatry unit and diagnosed with CAAS. Although her psychomotor excitation was ifficult to treat with medication alone, the combination of medication, psychological treatment and environmental coordination was effective. She was then able to move to a rehabilitation hospital.In addition to CAAS, psychological and environmental factors were involved in her psychomotor excitation. Therefore, it is considered that medication alone was not effective and that the combination of medication, psychological treatment and environmental coordination, known as the bio-psycho-social approach, was effective for improving the psychomotor excitation caused by CAAS.