BACKGROUND: Studies on gastrointestinal (GI) tract involvement in mantle cell lymphoma (MCL) are lacking. We investigated the clinical characteristics and prognosis of MCL with GI tract involvement. METHODS: We retrospectively analyzed 64 patients diagnosed with MCL from January 2009 to April 2017. At the time of MCL diagnosis, patients who were identified to have GI involvement by endoscopic or radiologic examination were assigned to the GI-MCL group. The other patients were assigned to the non GI-MCL group. RESULTS: The GI-MCL group included 28 patients (43.8%). The most common endoscopic finding of MCL was lymphomatous polyposis (20/28, 71.4%). The GI-MCL group had higher stage and International Prognostic Index status (P = 0.012 and P = 0.003, respectively). Among the total 51 GI lesions in the GI-MCL group, 31.4% (16/51) were detected only by endoscopic examinations and were not detected on CT or PET-CT. The cumulative incidence of recurrence was higher in the GI-MCL group compared with the non GI-MCL group but the difference was not statistically significant (P = 0.082). Stage (HR 1.994, 95% CI 1.007-3.948) and auto PBSCT (HR 0.133, 95% CI 0.041-0.437) were identified as independent predictive factors for recurrence. Recurrences at GI tract were identified in 59.1% (13/22) and 11.1% (2/18) of the GI-MCL and non GI-MCL group, respectively. Among 15 GI tract recurrences, five recurrences were detected only with endoscopic examinations. CONCLUSIONS: Endoscopy can reveal the GI involvement of MCL that is not visualized by radiological imaging. Endoscopic examinations are recommended during staging workup and the follow-up period of MCL patients.