The frequency and significance of pancreatic duct visualization by ultrasonography were correlated with endoscopic retrograde cholangiopancreatography or pancreatic computed tomography. The normal pancreatic duct was found to have parallel walls and to be less than 2 mm in internal diameter in the region of the body of the pancreas. The abnormal pancreatic duct had an internal diameter of 2 mm or greater or had walls that were nonparallel or convex outward (focal dilatation or beading). Pancreatic ducts were identified in approximately one-half of all patients evaluated. Failure to visualize an abnormally dilated pancreatic duct was secondary to distortion of pancreatic anatomy from large or multiple pseudocysts, calcific deposits within the pancreas, or technically poor visualization of the pancreas.