The aims of this study were to classify primary ileocolonic lymphomas according to colonoscopic findings and to determine the clinicopathologic relationship according to classes. Thirty-two patients (22 men, 10 women; age range 29 to 75 years) with primary malignant lymphoma of the terminal ileum and/or colorectum were studied. The clinicopathologic features were evaluated according to colonoscopic findings. Thirty-six lesions in 32 patients were endoscopically classified as follows: fungating (14, 39%), ulcerofungating (11, 31%), infiltrative (5, 14%), ulceroinfiltrative (4, 11%), and ulcerative (2, 6%). Location of the lesions was as follows: terminal ileum, 15 (42%); colorectum, 14 (39%); both regions, 7 (19%). The most common histopathologic types were diffuse large cell (22, 69%) and large cell immunoblastic (5, 16%). There was no relationship between the endoscopic findings and histologic types. In 9 patients (28%), the clinical manifestation was intussusception, and all were found endoscopically to have the fungating type lesion. Primary ileocolonic lymphomas can be classified endoscopically into fungating, ulcerative, infiltrative, ulcerofungating, and ulceroinfiltrative types. Among these, fungating and ulcerofungating are the most frequent. Intussusception is a common clinical finding in ileocolonic lymphomas, occurring mainly in patients with the fungating type of lesion.