Objective: To determine the relative benefit of staging laparoscopy in peripancreatic and biliary malignancies. Summary Background Data: Staging laparoscopy has been used in a variety of peripancreatic and biliary malignancies. The utility of the technique in subsets of these types of cancer has not been systematically compared. Methods: One hundred fifty-seven patients underwent laparoscopy after conventional tumor staging; 89 were also staged with laparoscopic ultrasonography. Diagnostic categories were cancer of the pancreatic head and uncinate process, cancer of the body and tail of pancreas, cancer of the extrahepatic bile duct, cancer of the gallbladder, and cancer of the ampulla of Vater/duodenum. Results: In patients with cancer of the head of the pancreas, metastatic disease or vascular invasion was discovered frequently by laparoscopy (31%), whereas in ampullary/duodenal cancer it was never found. The laparoscopic findings in cancer of the head of the pancreas had an important influence on treatment decisions, whereas in cancer of the ampulla/duodenum, laparoscopy had no effect on clinical decisions. Laparoscopy also substantially influenced the treatment of gallbladder cancer; in other tumor types, results were intermediate. Laparoscopic ultrasonography was valuable in cancer of the head of the pancreas. Conclusions: The utility of staging laparoscopy depends on diagnosis. It is recommended for continued use in pancreatic head and gallbladder cancers but not in ampullary malignancies.