In July, 1997, a 79-year-old woman visited a home doctor in Iwaki becase of abdorninal pain and appetite loss. Based on a gastroendoscopy finding showing a swollen papilla of Vater, she was admitted. to our hospital for further examination. The histology of the biapsied papilla showcd a praliferatian of atypical lymphoid cclls, which immunahis-tologically showed a positive staining for L-26. The lesion was pathologically suspected of MALT lymphoma. EndoscQpic ultrasonography showed a hypoechoic mass in the third layer of the wall of the papilla of Vater. Garium scintigraphy showed a hot spot in the region of the papilla of Vater. This case seemed to he the first case of MALT lymphoma iri the papilla of Vater reported in Japan.