Objective To explore the risk factors for surgical site infection (SSI) in patients after open biliary surgery excluding cholecystectomy. Methods Clinical data of 241 patients who underwent open biliary surgery excluding cholecystectomy in Eastern Hepatobiliary Surgery Hospital between April and May 2015 were analyzed retrospectively. The informed consents of all patients were obtained and the local ethical committee approval was received. There were 109 males and 132 females, aged from 24 to 77 and with a median age of 58 years old. General data of the patients were collected and SSI was observed. Related risk factors for SSI of the patients were analyzed using logistic regression, and the preventive treatments were summarized. Results The incidence of postoperative SSI was 8.3% (20/241). All SSI occurred on postoperative 1-14 d, with a median of 4 d. There were 10 cases whose SSI occurred at the abdomen, 8 cases at the biliary tract and 2 at the incision. Among the 20 cases with SSI, 15 cases suffered from bacterial infection, 1 case suffered from fungal infection and no bacteria was cultured in 4 cases. Multi-factor logistic regression analysis results showed that choledochojejunostomy, preoperative WBC >10×109/L and drainage tube indwelling time >8 d were the independent risk factors for SSI of these patients(OR=0.332,0.177,0.235;P<0.05).Conclusions SSI of patients with open biliary surgery excluding cholecystectomy is closely related to choledochojejunostomy, bile duct inflammation and postoperative drainage. It is of great significance to effectively control bile duct inflammation and ensure postoperative unobstructed drainage in preventing SSI after biliary surgery.