Metastatic tumors of the tonsils are rarer than primary tumors. Few cases of metastatic tonsillar tumor have been reported. A 51-year-old man expectorated a portion of a tumor from the left side of the pharynx after an operation for cancer metastatic to the lung. Biopsy revealed that the pharyngeal tumor was rectal cancer (adenocarcinoma) metastatic to the tonsil. To our knowledge, this is the first case of primary rectal cancer metastatic to the tonsil to be reported in Japan. The clinical features of metastatic tonsillar tumor are discussed.