In the past, it was not unusual for patients with hepatobiliary or pancreatic malignancies to come to laparotomy after conventional preoperative staging only to have metastases discovered during abdominal exploration. Surgeons from the Massachusetts General Hospital 1,2 and the Royal Infirmary in Edinburgh 3,4 introduced laparoscopic staging in an attempt to decrease the incidence of this problem. They reported that laparoscopy was an effective tool for detecting metastases that were not found by standard preoperative imaging. For example, in pancreatic carcinoma, previously undetected cancer was found by staging laparoscopy in about one third of patients. 1,3 Others, including our group, subsequently published studies that confirmed the value of staging laparoscopy in hepatobiliary and pancreatic malignancies. 5–17 Examination of the abdomen by laparoscopic ultrasound was introduced as an adjunct to laparoscopy because it can detect intraparenchymal lesions such as intrahepatic metastases, as well as enlarged lymph nodes, and vascular invasion by tumor. The Edinburgh group showed that this technique increased the yield of laparoscopic staging of pancreatic 3 and liver 4 tumors. Again, our experience and that of others supported their findings. 5–9,15,18,19 Initially we used these techniques mainly for cancers of the head of the pancreas. Encouraged by the results of that experience, we broadened their use to other peripancreatic and biliary malignancies, including ampullary and duodenal tumors. Staging laparoscopy has been used in a variety of malignancies, but there has not been a study comparing the relative utility of the technique in subsets of peripancreatic and biliary malignancies. The purpose of this study was to determine whether staging laparoscopy is of equal benefit in these different diagnostic categories, or whether its value is selective. If the latter were true, then selective use based on preoperative diagnosis might be recommended.