ObjectiveCurrent study was performed to evaluate the effectiveness of adequate lymph node dissection (ALND) in pathologically-confirmed node-negative cases with biliary tract cancers (BTCs). MethodsCases with pathologically confirmed BTCs from SEER data between 2000 and 2020 were retrospectively reviewed and analyzed. Comparative analyses in terms of clinic-pathological features and long-term survival based on the performance of ALND were performed. ALND was defined as a minimum number of resected lymph nodes with 6. ResultsA total of 1698 cases radically-resected cases with pathologically-confirmed BTCs were finally included (ALND received: 450, ALND not received: 1248). ALND (+) cases were generally in a more advanced stage than ALND (-) cases that the percentage of cases with T3-4 disease was significantly higher (P<0.001). Comparable incidence of receiving adjuvant chemotherapy (46.7% vs 46.1%, P=0.829) and adjuvant radiotherapy (16% vs 16.8%, P=0.686) were acquired between two groups. ALND (+) cases shared a more favorable prognosis than ALND (-) cases, especially when focused on different T categories. ALND was not a prognostic factor for radically resected cases with BTCs. Propensity score matching analysis was performed and the results were similar before matching. ConclusionALND was associated with obvious survival benefit among radically resected cases with pathologically confirmed node-negative BTCs and therefore the conventional application of ALND is strongly recommended, even for node-negative cases. Future multi-center studies focusing on the optimal number of resected lymph nodes regarding adequate lymphadenectomy for cases with BTCs, especially based on different tumor locations, are required.