Synchronous gastric cancer and primary small intestinal lymphoma are extremely rare.A 49-year-old woman was referred to our hospital with a history of upper abdominal pain for two weeks and was diagnosed with synchronous cancer.During hospitalization,the patient underwent laparoscopic distal gastrectomy+resection of bilateral ovaries+partial resection of both small intestine and descending colon.Pathological examination revealed a synchronous cancer consisting of early gastric cancer with poorly differentiated adenocarcinoma located in mucosa,with lymph node metastasis(3+/29)(T1N1M0,stageⅠB);and diffuse large B cell lymphoma of small intestine involving descending colon and bilateral ovaries,with lymph node metastasis(2+/5)(Ann ArborⅡE).The patient recovered well,without any obvious complications and was discharged on post-operative day 7.The patient received six cycles of chemotherapy after operation.She has been doing well with no evidence of recurrence for 13 mo. Synchronous gastric cancer and primary small intestinal lymphoma are extremely rare. A 49-year-old woman was referred to our hospital with a history of upper abdominal pain for two weeks and was diagnosed with synchronous cancer. Patients hospitalization, the patient underwent laparoscopic distal gastrectomy + resection of bilateral ovaries + partial resection of both small intestine and descending colon. Pathological examination revealed a synchronous cancer consisting of early gastric cancer with poorly differentiated adenocarcinoma located in mucosa, with lymph node metastasis (3 + / 29) (T1N1M0, stage IB) ; and diffuse large B cell lymphoma of small intestine involving descending colon and bilateral ovaries, with lymph node metastasis (2 + / 5) (Ann Arbor IIE). The patient recovered well, without any obvious complications and was discharged on post-operative day 7 The patient received six cycles of chemotherapy after operation. Has been doing well with no evidence of recurrence for 13 mo.