A 74-year-old female had repeated relapses of right lower abdominal pain; a colonoscopic examination showed a submucosal tumor of the appendix. Under provisional diagnosis of appendicitis caused by a submucosal tumor, a laparoscopic operation was performed. The laparoscopic observation did not reveal the typical finding of appendicitis. The tumor was thought to be a malignant neoplasm. The ileocecal region was excised with lymph node dissection. Macroscopically, the mass was localized in the appendix and did not infiltrate to the cecum. Histologically, the marginal zone consisted of lymphoid cells, and centrocyte-like cells were observed. Immunohistochemically, the tumor cells were positive for CD20 and CD79a and negative for CD3, CD10, and cyclin D1. The histological diagnosis was mucosa-associated lymphoid tissue (MALT) lymphoma of the appendix. Colonic MALT lymphoma is rare and rarely diagnosed before surgery. Furthermore, very few cases of the appendiceal MALT lymphoma have been reported. The laparoscopy was used in the case of a patient diagnosed with appendicitis and considered the possibility of MALT lymphoma of the appendix. We then performed an ileocecal resection, which is considered radical surgery. The present case suggests that a laparoscopic observation is helpful for the appropriate diagnosis and therapy of MALT lymphoma of the appendix.