Gallstone is a common disease with a 10% prevalence in the United States and Western Europe. However, it is only symptomatic in 20-30% of patients, with biliary pain "colic" being the most common symptom. Complications of asymptomatic gallstone disease are generally rare, with an incidence of <1 %/yr. The most common complications of gallstone disease are acute cholecystitis, acute pancreatitis, ascending cholangitis, and gangrenous gallbladder. Less frequent complications include Mirizzi syndrome, cholecystocholedochal fistula, and gallstone ileus. Mirizzi syndrome and cholecystocholedochal fistula are two manifestations of the same process that starts with impaction of a gallstone in the gallbladder neck that results in obstruction of the bile duct, causing jaundice. The gallstone may erode into the bile duct, causing cholecystocholedochal fistula. Gallstone ileus refers to small bowel obstruction resulting from the impaction of one or more gallstones after they have migrated through a cholecystoenteric fistula. An accurate diagnosis is essential to the management and prevention of further complications. A variety of imaging and endoscopic modalities are used to make the diagnosis once the condition is suspected clinically. Treatment should be tailored to each individual patient. Management choices include ERCP, lithotripsy (endoscopic or extracorporeal), and surgery. Prognosis is frequently related to early recognition, management of any comorbid conditions, and careful selection of treatment modalities.