The conventional methods of CT scan (CT), ultrasound (US), scintigraphy (SC), and laboratory tests (LDH, AP, 5-Nt) were prospectively compared in 135 patients with gastrointestinal carcinoma to define the most useful test to detect hepatic metastases. Thirty-six patients (26.7%) had hepatic metastases at laparotomy. Sensitivities were low: 46% for SC, 58% for US, 68% for CT and 63% for LDH. Accuracies ranged from 62% (LDH) to 78% (SC). No significant differences were found. Accurate and efficient detection of hepatic metastases is hampered by the relatively low sensitivity, specificity and accuracy of conventional imaging and laboratory tests.