BACKGROUND Lymph node metastasis is a poor prognostic factor for biliary tract cancers (BTCs). The optimal management of patients who have BTC with positive regional lymph nodes, including the impact of surgery and adjuvant therapy (AT), is unclear. METHODS This was a retrospective cohort study of patients who had T1-T3N1M0 gallbladder cancer (GBC) and intrahepatic cholangiocarcinoma (IHC) in the National Cancer Database (2004-2012). Patients were classified by treatment approach (nonoperative, surgery, surgery plus AT). Associations between the overall risk of death and treatment strategy were evaluated with multivariable Cox regression. RESULTS Rates of surgical resection were 84.1% for patients with GBC (n = 1335) and 36.6% for those with IHC (n = 1009). The median overall survival of patients in the nonoperative, surgery, and surgery plus AT group was 11.6, 13.3, and 19.6 months, respectively, for those with GBC (log-rank P < .001), and 12.7, 16.2, and 22.6 months, respectively, for those with IHC (log-rank P < .001), respectively. Compared with nonoperative therapy, surgery with or without AT was associated with a lower risk of death from GBC (surgery with AT: hazard ratio [HR], 0.59; 95% confidence interval [CI], 0.48-0.73; surgery without AT: HR, 0.71; 95% CI, 0.56-0.89) and from IHC (surgery with AT: HR, 0.52; 95% CI, 0.42-0.63; surgery without AT: HR, 0.70; 95% CI, 0.56-0.87). AT that included radiation was associated with a lower risk of death relative to surgery alone for patients with GBC regardless of margin status (margin-negative resection: HR, 0.66; 95% CI, 0.52-0.84; margin-positive resection: HR, 0.54; 95% CI, 0.39-0.75), but adjuvant chemotherapy alone was not. For patients with IHC, no survival benefit was detected with adjuvant chemotherapy or radiation for those who underwent either margin-positive or margin-negative resection. CONCLUSIONS The best outcomes for patients who have lymph node-positive BTCs are associated with margin-negative resection and, in those who have GBC, the inclusion of adjuvant chemotherapy with radiation regardless of margin status. Cancer 2017. © 2017 American Cancer Society.