Lymphoid polyp is a very rare disease that commonly occurs in the rectum. It is a benign, focal or diffuse lesion that typically occurs where clusters of lymphoid follicles are present. The polyp is composed of well differentiated lymphoid tissue. It can generally be differentiated from malignant lymphoma by the proliferation of normal lymphoid tissue, which has a prominent follicular pattern and a clearly defined germinal center. There have been only a few reports of lymphoid polyps of the rectum, and there have been no reports of lymphoid polyp in the ampulla of Vater. We experienced a case of lymphoid polyp in the ampulla of Vater associated with tubulopapillary adenoma, and the patient first presented with jaundice, weight loss and general weakness. (Korean J Gastrointest Endosc 2010;41:61-64)