Germinoma that occurs to the bilateral basal ganglia is exceedingly rare. The diagnosis can be diffi cult because of nonspecifi c clinical presentation and ill-defi ned abnormalities without a defi nite tumor mass on neuroimaging. Here, we presented a 24-year-old male who suffered from bizarre behavior and affective disturbance. At emergency room, the psychiatrist was consulted to evaluate his psychiatric abnormalities. Computed topography (CT) scan of brain revealed several cystic lesions with rim-like enhancement involving bilateral basal ganglia. Magnetic resonance (MR) imaging of brain showed multiple cystic lesions with irregular rim-like enhancement involving bilateral basal ganglia. Accordingly, stereotactic aspiration biopsy was performed by neurological surgeon, and pathological result revealed bilateral germinoma of basal ganglia. Then, the patient received chemotherapy followed by craniospinal irradiation. After craniospinal irradiation,MR imaging of brain was performed again, which showed complete regression. In conclusion, when the patient presented with bizarre behavior and affective disturbance with lesion located in basal ganglia, the differential diagnosis of
germinoma should be considered.