BACKGROUND The incidence of adenocarcinoma of the ampulla of Vater has been increasing over the past years. Nevertheless, it is still a rare disease and the prognostic factors predicting long-term survival are not sufficiently clarified. This study aims to evaluate the association between histopathological characteristics and long-term survival of patients with ampullary cancer after curative resection, as well as the efficiency of immunohistochemical expression of CK7, CK20, and CDX2 to distinguish the histopathological (intestinal or pancreaticobiliary) patterns. METHODS Demographic, histopathological data, pTNM stage, and immunohistochemical expression patterns were collected from 65 patients with adenocarcinoma of the ampulla of Vater. Five and 10-year overall and disease-free survival rates after curative resection were determined. RESULTS Of the 65 patients with ampullary carcinoma, 47 (72%) underwent radical resection. The 5- and 10-year overall survival rate was 46% and 37%, respectively. Our results demonstrate that the main prognostic factors were the presence and number of lymph node metastases, lymph node ratio (LNR), differentiation grade, and lymphovascular invasion. After multivariate analysis, only lymph node ratio ≥ 20% remained an independent prognostic factor of survival (HR: 2.63 95% CI: 1.05-6.61; p = 0.039). CONCLUSIONS Here, we demonstrated more evidence that the lymph node metastases are associated with poor prognosis in ampullary carcinoma. Particularly, the relation between the number of metastatic lymph nodes and the number of harvested lymph node (LNR) should be considered a major prognostic factor.