Abstract 155 jaundiced patients underwent laparotomy at the London Hospital between 1961 and 1965. In 3, the cause of the jaundice turned out to be medical rather than surgical. There was no mortality. The steroid diagnostic test, percutaneous liver biopsy, and percutaneous transhepatic cholangiography produced misleading or unhelpful results in some cases, and serious complications in others. If the cause of the jaundice is in doubt, observation of the patient should continue for not less than three weeks, by which time the diagnosis will often have become apparent. If a diagnosis has not been made after six weeks of jaundice, laparotomy should be carried out.