The main indications for intraoperative consultation of gastrointestinal tract, liver, and pancreatobiliary system are to evaluate the resection margin and to make a tissue diagnosis of lesions for which preoperative histology is not aviable for various reasons. Special situations include the evaluation of liver donor biopsies for the presence of steatosis and inflamation, or determination that ganglion cells are present in the bowel wall at the level where the anastomosis will be placed in case of Hirschprung's disease. The most worrisome pitfalls include differentiating pancreatic ductal carcinoma from chronic pancreatitis, distinguishing biliary tree and gallbladder carcinoma from reactive changes caused by inflammation, and recognizing the presence of diffuse adenocarcinoma at the resection margin of the esophagus and stomach. Keywords: frozen section - gastrointestinal tract - liver - gallbladder - extrahepatic biliary tree - pancreas.