A retrospective review of 211 computed tomographic (CT)-guided and 58 ultrasound (US)-guided biopsies of pancreatic lesions performed between 1985 and 1989 was undertaken to evaluate the accuracy of diagnosis and the number of complications. Combined CT and US accuracy in the diagnosis of malignancy was 93%. CT-guided biopsies had an accuracy of 86%, and US-guided biopsies had an accuracy of 95%. Accuracy was higher with larger masses (> 3.0 cm, 92%; < or = 3 cm, 81%) and larger needle sizes (16-19 gauge, 92%; 20-22 gauge, 85%) and when the mass was located in the body or tail of the pancreas (93%) rather than the head (84%). Major complications developed in three cases (1.1%). No biopsy-related deaths occurred. Needle passage through the gastrointestinal tract, including the colon, did not cause complications.