The prognostic significance of lymph node dissection (LND), the number and status of harvested lymph nodes (LNs), and the lymph node ratio (LNR) are still under debate in intrahepatic (ICC) and perihilar (PCC) cholangiocarcinoma. The aims of this study were to evaluate the prognostic value of the extent of LN dissection, the number of positive LNs, the distribution of positive LNs along different LN stations, and the LNR in a cohort of patients with ICC and PCC who underwent surgical resection and to compare the different prognostic values of lymph node involvement.A retrospective analysis was done evaluating extent of LND, number, status, and location of harvested LNs in a cohort of 145 patients with cholangiocarcinoma submitted to surgical resection with curative intent from 1990 to 2012.Seventy patients had ICC and 75 had PCC. The median survival times of patients with N0 and N+ tumors were 42 and 19 months in ICC patients (p = 0.05) and 42 and 22 months in PCC patients (p = 0.01). In patients without LN metastases, the median survival times of patients with up to three LNs retrieved and with more than three LNs retrieved were 38 and 69 months in ICC patients (p = 0.05) and 18 and 43 months in PCC patients (p = 0.04), respectively. In N+ patients, the location of positive LNs (hepatoduodenal ligament or other regional stations) did not influence overall survival in ICC or PCC patients (p = 0.6). The median survival times of patients with LNRs of 0 and >0.25 were 43 and 19 months in ICC patients (p = 0.01); the 0-0.25 group did not reach the value. In PCC patients, median survival of 0, 0-0.25, and >0.25 groups of patients were 42, 23, and 11 months (p = 0.01), respectively.LN metastasis is a major prognostic factor after surgical resection of cholangiocarcinoma. The number of harvested LNs and the LNR showed a high prognostic value in ICC and PCC.