objective: The aim of this prospective study was to assess the frequency and clinical significance of incidental findings on upper gastrointestinal endoscopic ultrasonography (EUS).  
Methods: Patients referred for upper gastrointestinal EUS were consecutively enrolled into this prospective study. Any coincidental abnormality found during standard EUS was considered an incidental finding. Significant incidental findings were defined as abnormalities that required further medical, surgical, or endoscopic intervention, including surveillance. 
Results: In 552 patients who underwent EUS, 41 incidental findings were detected in 39 patients (7.1%). Twenty-one abnormalities had clinical significance. The frequency of incidental findings increased significantly with increasing age (P = .001). The most frequent incidental findings were gallstones, subepithelial lesions, and pancreatic lesions. 
Conclusions: Incidental findings on EUS are not uncommon in clinical practice and might be a clue to a significant pathology. The appropriate extent of evaluation of incidental findings noted during a standard EUS procedure warrants further research yet to be defined. 

Keywords: incidental findings, endosonography, pancreatic neoplasms, diagnostic imaging