Septic complications and renal insufficiency following biliary tract surgery are frequently seen in patients with obstructive jaundice. The precise mechanisms for understanding the susceptibility of the jaundiced patients to sepsis are, however, not clear. The present study aimed at investigating the influence of biliary obstruction on the reticuloendothelial function and bacterial translocation at various time intervals in the rat. Reticuloendothelial system (RES) function, as evaluated by measuring blood clearance of intravenously injected 125I-labeled Escherichia coli, and bacterial translocation were studied 3 days and 1, 2, and 3 weeks following either sham operation or common bile duct ligation (CBDL) and transection in the rat. RES function was significantly impaired and renal uptake of radiolabeled E. coli was significantly higher in jaundiced animals from Day 3 and on after CBDL (P < 0.01) concomitant with elevation of plasma levels of bilirubin and liver enzymes (P < 0.001) compared with their corresponding controls. The incidence of bacterial translocation 3 days and 1 and 2 weeks after biliary obstruction significantly increased (P < 0.05). We conclude that RES phagocytic function is impaired and the incidence of bacterial translocation is increased in jaundiced rats. These findings might contribute to explain the high susceptibility of postoperative septic complications and renal dysfunction in patients with obstructive jaundice.