Pancreatic head cancer accompanied by obstructive jaundice is a common clinical situation. The aim of this study was to assess the impact of preoperative biliary drainage (PBD) on clinical outcomes in patients with severe obstructive jaundice. Patients with a bilirubin level of ≥250 μmol/L at diagnosis who underwent PBD were included. The primary endpoints and secondary endpoints were the postoperative severe complications rates. Secondary endpoints were the degree of improvement in general condition, predictors of severe postoperative complications, and the impact of PBD on patients with bilirubin levels >300 μmol/L. In total, 289 patients were included, and 188 patients (65.1%) underwent PBD. The patients who met the American Society of Anesthesiologists (ASA) classification II-III stages decreased from 119 to 100 ( P = 0.047) after PBD. The overall severe complications were significantly more frequent in the direct surgery (DS) group than in the PBD group (34.7% vs. 22.9%, P = 0.031), especially the postoperative hemorrhage (6/43 [14.0%] vs. 9/35 [25.7%], P = 0.038) and intra-abdominal infection (6/43 [14.0%] vs. 10/35 [28.6%], P = 0.018). The ASA classifications II-III (odds ratio [OR]=2.89, 95% confidence interval [CI]: 1.38-4.31), P = 0.01) and DS (OR = 3.65, 95% CI: 1.45-7.08; P = 0.003) were independently associated with severe postoperative complications. The occurrence rate of severe postoperative complications in patients with a bilirubin level >300 μmol/L who underwent PBD was significantly lower than in patients who underwent DS (25.6% vs. 40.6%, P = 0.028), but the benefit of PBD was not observed in patients who had a bilirubin level between 250 and 300 μmol/L. PBD is useful in reducing severe postoperative complications, especially in patients with bilirubin levels >300 μmol/L.