Lymphoma is a major medical problem as it represents the 5th common malignancy world wide and it is continuing to increase rapidly. Non Hodgkin's lymphomas comprise 70% of malignant lymphoma from which extra nodal group accounts for 30%. Helical CT has important roles in the work up of lymphoma cases. It has a variable degree of sensitivity in detection of lymphomatous infiltration of abdominal organs, however, its most important role is the staging and follow up of the disease during the treatment as well as long term follow up to detect relapse. Conclusion: CT is the routine investigation that should be used in the work-up of a case of abdominal extra nodal lymphoma :1.As regard diagnosis, it has a variable degree of accuracy in detecting lymphomatous involvement of different abdominal structures.2.CT is used as guidance for obtaining tissue sample for histopathological diagnosis.3. CT is the investigation of choice in staging of lymphoma because of its accuracy in scanning supra and infra-diaphragmatic structures as well as its accuracy in scanning different L.N groups.4. CT is used efficiently in follow up of the disease to assess therapeutic response, confirm remission, and in long term follow up to detect relapse