Objective: To explore the diagnosis and treatment of primary gastrointestinal malignant lymphoma (PGIML). Methods: The clinical data of 34 PGIML patients admitted to our department from January 1995 to December 2010 were retrospectively analyzed. Results: The patients of whole group comprised 23 male and 11 female cases, whose ages ranged from 22 to 74 years (average of 51.8). All patients were pathologically confirmed to have PGIML, of whom, in 24 cases the primary tumor was located in the stomach and 10 in the intestinal tract. The initial onset symptoms of the 24 patients with gastric lymphoma were epigastric pain or discomfort, and in 8 cases was accompanied with melena and 3 cases with fever. While the initial symptoms in the 10 patients with intestinal lymphoma were abdominal pain and mass, and 4 cases were complicated with melena, 2 cases with symptoms of bowel obstruction and 1 case had signs of intestinal perforation. PGIML was proved by gastroscopic biopsy in only 5 of the 24 patients with gastric lymphoma, and diagnosed by colonoscopic biopsy in only one of 10 patients with intestinal lymphoma. The preoperative diagnosis rate was 17.64% (6/34). The patients were misdiagnosed for 2 to 8 months (average of 4.5 mionths). All patients underwent surgical treatment, of whom, 32 cases underwent radical tumor resection (8 cases of radical gastrectomy, 14 cases of radical distal gastrectomy, 3 cases of partial resection of small intestine, 6 cases of right radical hemicolectomy and 1 case of radical resection of rectal tumor) and 2 cases underwent palliative subtotal gastrectomy. Thirty-one patients received chemotherapy after surgery. The immunohistochemical classifications of the 34 patients were B cell lymphoma (27 cases), T cell lymphoma (4 cases), and “non-T, non-B” lymphoma (3 cases). All patients were followed up for 5 to 62 months, and the 1-, 3- and 5-year survival rates were 82.35%, 64.71% and 47.05%, respectively. Conclusion: The preoperative diagnosis rate of PGIML is relatively low, and gastrointestinal endoscopy and biopsy are the main approaches for preoperative diagnosis. Comprehensive treatment including surgery and chemotherapy can confer a good therapeutic effect.