OBJECTIVES: The aims of this study were to evaluate the diagnostic accuracy of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in patients with suspected pancreatic cancer, and to assess immediate, acute, and 30-day complications related to EUS-FNA. METHODS: All patients with suspected pancreatic cancer were prospectively evaluated. A single gastroenterologist performed all EUS-FNAs in the presence of a cytopathologist. Immediate complications were evaluated in all patients. An experienced nurse called patients 24-72 h and 30 days after the procedure. Reference standard for the classification of the final diagnosis included: surgery (n = 48), clinical or imaging follow-up (n - 63), or death from the disease (n = 47). RESULTS: A total of 158 patients (mean age 62.3 yr) underwent EUS-FNA during the study period. The mean tumor size was 32 × 26 mm. The median number of passes was three (range one to 10). Of these patients, 44% had at least one failed attempt at tissue diagnosis before EUS-FNA. The sensitivity, specificity, PPV, NPV, and accuracy of EUS-FNA in solid pancreatic masses were 84.3%, 97%, 99%, 64%, and 84%, respectively. Immediate self-limited complications occurred in 10 of the 158 EUS-FNAs (6.3%). Of 90 patients contacted at 24-72 h, 78 patients (87%) responded. Of the 90 patients, 20 (22%) reported at least one symptom, all of which were minor except in three cases (one self-limited acute pancreatitis and two emergency room visits, one of which led to admission). In all, 83 patients were contacted at 30 days, and 82% responded. No additional or continued complications were reported. CONCLUSIONS: EUS-FNA is highly accurate in identifying patients with suspected pancreatic cancer, especially when other modalities have failed. Major complications after EUS-FNA are rare, and minor complications are similar to those reported for upper endoscopy. It seems that follow-up at 1 wk might capture all of the adverse events related to EUS-FNA. © 2003 by Am. Coll. of Gastroenterology.