We discussed usefulness of cytology for rapid intraoperative diagnosis of intracranial tumors using frozen section. Twenty five cases of intracranial tumors (6 cases of astrocytoma, 6 cases of glioblastoma multiforme, 4 cases of meningioma, 2 cases of pituitary adenoma, 1 case of ependymoma and 6 cases of metastatic carcinoma) were observed by cytological specimen, frozen section and formalin fixed-paraffin embedded section. When only frozen section were used for histopathological diagnosis, it was difficult to diagnose in a few case of astrocytic tumors by artifact in freezing process. When only cytological specimen were used for diagnosis, histological findings, for example pseudopalisading around necrosis in glioblastoma or rosette formation in ependymoma, were not identified. However, diagnostic accuracy were improved when both cytological and frozen specimen were used if adequate material were obtained for diagnosis. In conclusion, cytological approach used in addition to frozen section was useful for rapid intraoperative diagnosis.