Biliary tract cancer (BTC) has been inconsistently identified according to its location in epidemiological and clinical studies. This study retrospectively reviewed the treatment pattern and prognosis of BTC according to tumor location using the Korea Central Cancer Registry data of 97,676 patients with BTC from 2006 to 2017. The proportion of localized and regional Surveillance, Epidemiology, and End Results (SEER) stage was the highest in ampulla of Vater (AoV, 78.