Authors experienced a case of human infection with Anisakis sp. in left tonsil. The case was 27 year Korean female who visited Department of Otolaryngology, Severance Hospital with the chief complaints of swollowing difficulty, and the sensation of a foreign body in the throat, on November 20th 1968. Physical examination of the oral cavity revealed that both palatin tonsil were chronically enlarged. A larval worm was found in crypt of the upper portion of the left palatin tonsil. Chief complaints of the patient was improved after removal of it by forceps. The greyish white living worm was fixed in lactophenol solution for morphological study. The worm measured 36 mm in length by 0.6 mm in width, 2.4 mm in esophageal length, 1.4 mm in ventricule, 0.1 mm in tail length, and 0.025 mm in caudal spine length, respectively and histological study was carried out from the serial section of the larva which was stained with hematoxylin eosin. Authors identified that the larva was Anisakis species.