ObjectiveThis study compared the therapeutic effects of different timing for PTCD and ERCP in obstructive severe acute biliary pancreatitis.MethodsWe evaluated the clinical data for 62 patients with obstructive severe acute biliary pancreatitis in Beijing Tiantan Hospital. The study was performed from July, 2013 to July, 2019. According to the treatment, patients were divided into three groups: conservative group (n=16), PTCD group (n=22) and ERCP group (n=24), and the PTCD and ERCP groups were divided into early (24-72 h) and delayed (>72 h) groups. Laboratory indices, recovery time of liver function, remission time of abdominal pain, hospitalization length, curability and complications were compared among groups.ResultsThe average hospitalization length, time for abdominal pain relief and laboratory indices recovery were shorter (p <0.05) in early PTCD and ERCP groups than in the conservative group. Further, the average days of hospitalization in the ERCP group was shorter (p <0.05) than in the PTCD group. The complications were low in ERCP (33.33%) and PTCD (27.27%) groups, compared to the conservative group (62.50%).ConclusionsFor patients who cannot determine the severity of biliary pancreatitis in the first place and exclude patients who have performed ERCP within 24 hours, ERCP is recommended for relieving obstruction of obstructive severe acute biliary pancreatitis within 24-72 hours, however, PTCD may be considered in patients failed to be cured by ERCP.