The role of hepatobiliary isotopic scanning after liver transplantation was assessed in the first 12 adult patients in the Pilot National Liver Transplantation Programme who underwent this procedure at the Royal Prince Alfred Hospital. Iminodiacetic-acid derivative (HIDA) studies were useful in the non-invasive assessment of hepatic function and biliary excretion. The following four clinical situations were assessed by hepatobiliary scans: early graft function; rejection episodes; vascular complications; and biliary-tract problems. Nuclear medicine has an important and valuable role in the postoperative monitoring of patients after liver transplantation. The studies are non-invasive and can be performed readily at the bedside in the intensive care unit.