Eight patients scheduled for cholecystectomy were studied with the aim of defining the pattern of portal venous blood flow in the recovery phase after anaesthesia and abdominal surgery. The continuous thermodilution technique was used for measuring portal flow, via a thermodilution catheter placed in the portal vein after intraoperative umbilico-portal cannulation. Measurement of portal blood flow was begun during surgery and was repeated 2, 4, 6, 8, 12, 24 and 48 hours postoperatively. The flow rate 48 hours after surgery was 977 +/- 182 ml.min-1 (mean +/- SEM), compared with 605 +/- 89 ml.min-1 (p less than 0.05) during cholecystectomy. No significant deviation from the mean intraoperative portal blood flow was found at any of the post-operative measuring points prior to 48 hours. The study's results confirmed the applicability of the thermodilution technique for measuring portal blood flow in awake patients after surgery.