Small bowel adenocarcinoma (SBA) is a relatively rare malignancy in gastrointestinal tumors. In addition, the difficulty of early diagnosis, its poor prognosis compared to large bowel adenocarcinoma, and inadequate treatment experiences due to lack of prospective randomized trials make it necessary to explore the characteristics of the disease for early diagnosis and treatment.Patients diagnosed with primary malignant tumor of small intestine in West China Hospital of Sichuan University between January 2001 and 2013 were reviewed retrospectively. A total of 208 patients with SBA were selected and 160 patients with duodenal periampullary tumor were excluded. Forty-two cases of patients were finally enrolled for statistical analysis as 6 patients were lost of follow-up. The clinical characteristics, the response to treatment and their overall survival (OS) time were reviewed and analyzed.Of the 42 patients, 11 (26.2%) primary tumors were originated from duodenum, 29 (69.0%) from jejunum, and 2 (4.8%) from ileum. All patients (64.3% male; median age, 54.7 years) included in this study underwent primary resection of the tumor to confirm final diagnosis. Three-year survival rate is 21% and 5-year survival rate is 9%. Median OS were 24.2 months (95% CI: 4.0-72.0). The univariate predictors for prognosis of SBA were as follows: age (P = .021), severe intestinal symptoms at first diagnosis (P < .001), T4 of tumor stage (P = .011), tumor size (P = .004), relatively late clinical stage (P < .001), peritoneal metastasis (P < .001), and no chemotherapy (P = .011). The multivariate predictors for poor prognosis were age of more than 60 years old (P = .035), intestinal obstruction or perforation at first diagnosis (P = .026), relatively late clinical stage (P = .000), and no chemotherapy (P = .027).SBA was a relatively rare malignancy that was difficult for early diagnosis and treatment. Intestinal obstruction was the common clinical manifestation at first diagnosis, with a tendency of early peritoneal metastasis. Precaution of the disease in early phase, radical resection of the primary tumor while resectable, followed with in-time chemotherapy might improve prognosis and survival of patients with SBA.