Between 1982 and 1986, 410 preoperative percutaneous fine needle aspiration (FNA) biopsies of the pancreas were performed on 316 patients clinically suspected of having a malignant pancreatic tumor. Of 58 patients with pancreatic carcinomas subsequently confirmed by histologic investigation, the FNA biopsy yielded a cytologically positive diagnosis of carcinoma in 39 cases (67.2%) and suspicious findings in another 5 cases (8.6%). In 14 cases of malignancy (24.1%), the FNA puncture failed to sample material from the tumor; hence, the cytologic evaluation yielded false-negative results. Of 21 patients with inflammatory disorders of the pancreas, cytologically suspicious cells were observed in 5 cases (23.8%); in none of those 5 cases did the histologic examination show any evidence of carcinoma. This indicates that caution should be taken not to cytologically over-diagnose cases of pancreatitis. On the whole, cytology proved to be a valuable method for the diagnosis of pancreatic carcinoma; it provided the highest rate of positive results in comparison with other modern clinical diagnostic methods. Furthermore, cytology may improve the diagnostic results even in those cases with clinically negative or merely suspicious findings. FNA punctures of the pancreas produced no serious complications in this series.