A 26 year-old man, who was treated for meningitis in our hospital previously, was rehospitalized 1 year later because he developed disturbance of consciousness, gait disturbance and urinary incontinence. Blood examination revealed accelerated ESR, elevated GPT, slight elevation of serum Ca, strong positive CRP, and a decrease in PHA and Con A. ACE was within normal range and tuberculin reaction was negative. Lumbar puncture revealed that the initial pressure was 310 mmH2O, cells were 152/3, and protein was 343 mg/dl. Bilateral hilar lymphadenopathy was absent in chest X ray film. Head CT revealed enlarged lateral ventricles and irregularly enhancing nodular lesions in the anterior half of the falx cerebri, and abnormally strong enhancement of the choroid plexus. Ventriculoperitoneal shunt was performed. As a diagnosis was difficult to obtain from the clinical data, biopsy of the nodular lesions was performed. The histopathologic diagnosis was sarcoidosis. Steroid hormone was administered thereafter, and the nodular lesions of the falx disappeared in the follow-up. In the literature, only 8 cases of sarcoidosis of the dura mater have been reported. Since intracranial sarcoidosis is a part of systemic sarcoidosis, its diagnosis is not difficult in most cases. However, in cases difficult to diagnose as in our case, biopsy may be necessary. When nodular lesion occurs in the dura mater, sarcoidosis must be included as a possibility in the differential diagnosis in addition to the usual meningioma, lymphoma, and metastatic brain tumor.