We describe a 65-year-old man diagnosed with Burkitt's lymphoma arising from the intestine. The tumor cells had a mature B-cell immunophenotype and rearrangement of the c-myc gene. The patient was treated with intensive multiagent chemotherapy. After four courses of chemotherapy, an ileus developed due to a residual abdominal disease. We administered rituximab in combination with the same chemotherapy regimen. A dramatic clinical improvement was observed and abnormal uptake by 18F-fluorodeoxyglucose positron emission tomography disappeared. The patient experienced complete remission for 1 year. This encouraging result indicates that rituximab might be an important treatment choice in management of Burkitt's lymphoma.