The experience of the Institut Gustave-Roussy in the diagnosis of hepatic and pancreatic lesions by fine needle aspiration (FNA) is reported. Totals of 116 consecutive percutaneous ultrasound-guided FNAs of the liver and 27 of the pancreas were performed without complication in patients with ultrasonically suspected neoplastic lesions. In 12 cases, the material was not suitable for diagnosis. In the liver, 97 cases were correctly diagnosed and confirmed by follow-up. Immunohistologic studies were helpful in distinguishing primary liver tumors from other malignancies. One false-positive result was reported. In the pancreas, malignancy was detected in 17 cases. Cytology alone provided the correct tumor diagnosis in 15 cases: 10 primary carcinomas, 2 endocrine tumors and 3 metastases. The sensitivities of FNA in this study were 87.6% for the liver and 85% for the pancreas, similar to those reported in other series.