Choledocholithiasis refers to stones in the common bile duct. Stones can be primary, forming directly in the bile duct, or secondary, originating from the gallbladder. Clinical features include biliary colic, jaundice, fever, and complications like cholangitis. Investigations include ultrasound, MRCP, CT, and ERCP. Treatment involves ERCP with sphincterotomy and stone extraction, or open exploration during cholecystectomy. For retained stones, techniques include T-tube flushing or reoperation with transduodenal sphincteroplasty or choledochojejunostomy.