We had experienced a case of metastatic papillary adenocarcinoma in the posterior fossa originating from the maxillary sinus, though there is general agreement that the commonest orgin of the metastatic intracranial tumors is bronchogenic carcinoma with carcinoma of the breast a close second;stomach and kidney come next and the carcinomas metastasize to the supratentorial cavity mostly. The patient was 41-year-old male who had complained of severe frontal headache, vomiting and loss of weight for about 40 days prior to admission. The tumor was located between the cerebellum and the meninges, and well demarcated, yellowhish and soft. We could remove it easily. Microscopic findings of the tumor showed papillomatous overgrowth of moderately differentiated signet ring cells with areas of necrosis and frequent mitosis. PAS staining revealed the presence of PAS positive materials in those cells.