Endotoxinemia in patients with obstructive jaundice is linked to acute renal failure and sepsis and remains a major cause of complications during postoperative treatment. The current study examines the mechanisms of endotoxinemia in the portal and the systemic circulation in obstructive jaundice. As an experimental model of the disease we used rabbits subjected to sham operation. Serum total bilirubin aminotransferases and endotoxin concentrations were determined at 2, 5, 8, and 13 days after operation. Endotoxin concentrations were estimated by the limulus lysate endotoxin test. A high frequency of portal or systemic endotoxinemia is observed in obstructive jaundice, but no difference between endotoxinemia levels in the portal and systemic circulation was observed.