Increasingly frequent reports of lymphoma with a gastro-intestinal primary location have stimulated much interest. Symptomatology has been shown not to be very specific, and scarcely different to that of other gastro-intestinal pathologics, both benign and malignant. The identification of some endoscopic pictures which suggest a lymphomatosic pathology and the possibility of collecting targeted biopsy samples, have placed endoscopy among the most important tests in the diagnostic and staging phase of gastro-intestinal lymphoma. This technique plays an equally important role in the follow-up period, since it allows the therapeutic efficacy of treatment to be assessed and the early identification of possible relapses.