Anisakis is an accidental parasitic infection caused by the larvae of marine mammals. An individual becomes infected with a larval form of the nematode Anisakis by consuming raw or undercooked fish containing the parasite. Generally, the clincal symptoms are characterized by severe cramping abdomianl pain, nausea, vomiting, and an epigastric full sensation. A case was recently experienced by a patient who suffered acute esophageal anisakiasis, and had a history of eating raw sea fish. His symptoms included substernal chest pain and odynophagia. Early endoscopic examination revealed a whitish linear worm in the mid-esophagus, which was removed by biopsy forceps. (Korean J Gastrointest Endosc 19: 597∼600, 1999)