The gastrointestinal tract is the commonest extra-nodal site of involvement in B-cell lymphomas and poses particular diagnostic and management problems, including therapy induced bowel perforation and bleeding. Rituximab therapy has demonstrated a significant increase in the complete response rate and prolongs disease free (DFS) and overall survival (OS) in diffuse large B-cell lymphoma. The extra efficacy of rituximab based therapies might increase the immediate complications peculiar to lymphomas of the gastrointestinal tract, particularly perforation. This has not been studied previously. We have reviewed treatment related complications and outcome in 40 cases of primary gastric and intestinal B-cell lymphoma (36 Diffuse Large B-Cell lymphoma, 3 Burkitt Lymphoma, 1 post transplant lymphoproliferative disorder) of the gastrointestinal tract (esophagus 1 case, stomach 21, small bowel 14, ileocaecal 3, large bowel 7;some patients had more than one site involved) over a 25 year period. Rituximab therapy was added to conventional therapy for patients treated in the last 5 years. There were 10 patients (median age 60; range 35–79; M: F=1.5:1) treated with regimens that included rituximab and 30 patients (median age 56; range 12–91; M: F=1.5:1) treated without rituximab. This included chemotherapy (12 patients), surgery alone (2 patients), both surgery and chemotherapy (14 patients) and radiotherapy (1 patient). One patient was not fit for any type of therapy. Complications occurred in 7 patients not treated with rituximab and in 1 patient who received this treatment. Complications included perforation (3 patients treated without rituximab; 1 patient in the rituximab group), bleeding (3 patients treated without rituximab; no episodes of bleeding in the rituximab group) and intestinal obstruction (3 patients in the group not treated with rituximab; no episodes of obstruction in the rituximab treated group). The difference in the complication rate between the two groups was not significant. Five patients in the group that did not receive rituximab died; two of neutropenic sepsis, two of gastric perforation and the other of operative complications. There were no treatment related deaths in the rituximab group. There was one patient in the rituximab treated group and three patients in the group that did not receive rituximab who had refractory disease. The median DFS was 21 and 14 months in patients treated with and without rituximab, respectively (p=0.6). The mean OS was 35 months in the rituximab treated group and 45 months in the group that did not receive rituximab (p = 0.9). There is presently no evidence that rituximab should be withheld early in the treatment of primary gastro-intestinal B-cell lymphomas because of concern about increasing the complication rate.