Despite the advances made since the introduction of ultrasonography, computed tomography and magnetic resonance imaging, a wide discrepancy may occur between preoperative and peroperative staging of gastrointestinal malignancy with liver and peritoneal metastases. Diagnostic laparoscopy performed immediately before a planned laparotomy can provide valuable information for the accurate assessment and appropriate management of some forms of gastrointestinal malignancy, especially that of the liver and pancreas. For evaluation of small liver and retroperitoneal malignancies, intraoperative ultrasonography performed by laparotomy is of proven value. It is now technically possible to perform ultrasonography through a laparoscopic cannula using high-resolution ultrasonographic transducers. This combination of laparoscopy and ultrasonography was studied in 25 patients with established liver lesions, carcinoma of the gallbladder or pancreatic cancer. Additional information leading to a change in surgical approach was obtained in 20 patients. Laparoscopic ultrasonography, although still in a preliminary phase of development, is a simple and reliable technique that will contribute to more accurate staging of intra-abdominal malignancy.