Adenocarcinoma arising from the ampulla of Vater is a rare disease and has limited data regarding outcome of chemotherapy. The ampulla of Vater is a heterogeneous junctional structure located at the union of the common bile duct, the pancreatic duct, and the small intestine. Thus, ampullary adenocarcinoma is classified as either intestinal type or pancreatobiliary type. We investigated the efficacy of the XELOX (capecitabine plus oxaliplatin) chemotherapy in patients with recurrent or metastatic ampullary adenocarcinoma, and analyzed the histopathologic features and outcomes. From November 2009 to December 2011, 21 patients were treated with XELOX regimen. XELOX was administered in outpatient clinic every 3 weeks according to the following protocol: oral administration of capecitabine 750 mg/m² twice a day on days 1-14 and intravenous injection of oxaliplatin 130 mg/m² on day 1. With follow-up of median 16.6 months, median time to progression (TTP) was 7.6 months (95% confidence interval [CI], 6.7-8.5), and median overall survival was 19.7 months (95% CI, 14.8-23.6). Two patients (9%) achieved complete response and 6 patients (29%) showed partial response. In subgroup analysis with tissue specimens obtained from 17 patients, median TTP was longer among patients with the intestinal-type adenocarcinoma (n = 7), compared to those with the pancreatobiliary type (n = 10) (13.1 vs. 6.4 months, P = 0.038). The most common grade 3-4 adverse event was neutropenia (27%), and most events were mild. XELOX chemotherapy shows favorable efficacy with manageable toxicity for advanced intestinal-type ampullary adenocarcinoma.