A case of Pseudoterranova decipiens infection was found in a 43-year-old man by gastroendoscopic examination on August 20, 1996. On August 6, 1996, he visited a local clinic, complaining of epigastric pain two days after eating raw marine fishes. Although the symptoms were relieved soon, endoscopic examination was done for differential diagnosis. A white, live nematode larva was removed from the fundus of the stomach. The larva was $38.3{ imes}1.0{;}mm$ in size and had a cecum reaching to the mid-level of the ventriculus. A lot of transverse striations were regularly arranged on the cuticle of its body surface, but the boring tooth and mucron were not observed at both ends of the worm. The worm was identified as the 4th stage larva of P. decipiens.