Definitive diagnosis of pancreatic cancer presents difficulties in that positive identification is often possible only by intraoperative biopsy. Recently, ultrasonic visualization of the pancreas has made preoperative diagnosis possible by furnishing a guide to percutaneous biopsy via a flexible 23-gauge, 0.6 mm needle. Ten patients with pancreatic carcinoma were biopsied with a fine needle under the ultrasonic image. Malignant cells were detected in 8 cases. In 2 cases, however, hypocellularity of the specimen lead to a false negative result. No complication was encountered in this series.