Background and Aims Obstructive jaundice is a common clinical feature of malignant tumors of the head of the pancreas and periampullary region, which can lead to various pathophysiological changes in the body, thereby increasing the risk of complications after pancreaticoduodenectomy (PD). However, there have been significant discrepancies in previous studies regarding the benefits of preoperative biliary drainage (PBD) in such patients and the indications for PBD. Therefore, this study was conducted to further analyze the necessity and indications for PBD in patients with different degrees of jaundice.Methods The clinical data of 358 patients with obstructive jaundice who underwent PD in the First Affiliated Hospital of Naval Medical University from 2016 to 2018 were retrospectively analyzed (including patients undergoing PBD and those undergoing direct surgery). Based on preoperative serum total bilirubin (TBIL) level (TBIL level before drainage for patients undergoing PBD), the patients were divided into mild jaundice group (TBIL <250 μmol/L) and severe jaundice group (TBIL ≥250 μmol/L). The main clinical variables between patients undergoing PBD and those undergoing direct surgery were compared in both groups separately.Results There were 183 cases in the mild jaundice group, including 34 cases undergoing PBD and 149 cases undergoing direct surgery, and 175 cases in the severe jaundice group, including 75 cases undergoing PBD and 100 cases undergoing direct surgery. In both the mild and severe jaundice groups, there were some differences in preoperative baseline data, intraoperative indicators, and postoperative pathology between patients who underwent PBD and those who underwent direct surgery (some P<0.05). Regarding postoperative outcomes, there were no statistically significant differences in the incidence rates of total complications, severe complications, specific complications, and perioperative death, as well as transfusion rate, and length of hospital stay between patients who underwent PBD and those who underwent direct surgery in the mild jaundice group (all P>0.05). However, in the severe jaundice group, patients who underwent PBD had significantly lower incidence of overall complication, incidence of postoperative bleeding, transfusion rate, and incidence of gastric emptying disorder compared to those who underwent direct surgery (all P<0.05). Multivariate regression analysis showed that PBD was an independent influencing factor for overall postoperative complications (OR=0.444, 95% CI=0.237-0.832, P=0.011) and postoperative bleeding (OR=0.293, 95% CI=0.088-0.978, P=0.046) in patients with severe obstructive jaundice after PD.Conclusion For patients with mild jaundice, the benefit of preoperative PBD before PD is limited, and routine PBD is not recommended. For patients with severe jaundice, PBD can effectively improve postoperative outcomes of PD, and it is recommended to perform PBD when TBIL is ≥250 μmol/L.