Intracranial aspergillosis of the lateral ventricle is a rare condition and has not been reported in a schizophrenic patient. We report a 39-year-old male patient with underlying schizophrenia and a rapid deterioration of consciousness. Initial cranial computed tomographic images revealed focal dilatation of the posterior part of the right lateral ventricle with a severe mass effect and midline shift. The patient received an emergency endoscopic ventriculostomy, and the resected mass was proven to be aspergillus. The patient was postoperatively treated by prolonged external ventricular drainage and antifungal medication, with no recurrence of aspergillosis at the 12-month follow-up.