Primary gastric lymphoma (PGL) is not a common cancer and account for 10% of malignant lymphoma and 5% of gastric cancer. The correlation with Helicobacter pylori (H. pylori) infection with mucosa associated lymphoepithelial tumor (MALT) is now well documented and some of the low grade MALT can be cured sorely by triple agent eradication therapy. The most common type of PGL is diffuse large B cell lymphoma which now can be successfully treated with chemotherapy alone. There is still no consensus on the optimal treatment for PGL. In the recent 10 years chemotherapy combined with anti-CD 20 monoclonal antibody such as rituximab, achieved higher complete response rate and more than 80% are long-term survival. The so-called R-CHOP (rituximab, cyclophosphamide, vincristin, prednisolone) now become the new gold standard therapy. The role of surgical resection prior to chemotherapy is controversial and not commonly applied in recent publications. Yet some cases of suboptimal response to R-CHOP or patient is too fragile to tolerate the immuno-chemotherapy will be feasible to surgical resection as a salvage or alternative therapy. The radiotherapy as an adjuvant therapy is less commonly considered. Patients with advanced PGL with high international prognostic index risk and along with co-morbidity diseases are prone to get treatment related complications from above-mentioned modality of treatment, such as GI perforation, neutropenic septicemia, pulmonary infection, fulminate heaptitis B reactivation, respiratory and cardiac impairment can be seen.