We report the case of a 77-year-old man who developed low grade B cell non-Hodgkin's lymphoma of the gastric stump 5 years after undergoing a distal gastrectomy for benign gastric ulcer. Lymphoma occurring in the post-operative stomach would appear to be very rare, with only 14 previously recorded cases. The median period of lymphoma onset after ulcer surgery is about 20 years (range 9-43 years) and gastric remnants of lymphoma are generally diagnosed in low stage, when surgery is possible and makes the prognosis good. The clinical case presented herein is quite different from the others. The patient developed lymphoma within 5 years of the ulcer surgery, thus, earlier than generally reported in literature; he presented with massive regional and extra-regional nodes involvement and liver metastases and he poorly responded to antiblastic chemotherapy. The pathogenetic role of Helicobacter pylori (HP) infection and the possibility of malignant lymphoma developing in the gastric stump are discussed.