Elevation of carbohydrate antigen 19-9 has been observed in jaundiced patients with benign biliary tract diseases. No clear answer has explained that relationship. Patients with liver hydatidosis and frank intrabiliary rupture could present obstructive jaundice due to the presence of liver cyst material in the bile duct. We present two cases of huge elevation of carbohydrate antigen 19-9 in jaundiced patients with liver hydatidosis and biliocystic communication, and we assess the different theories presented in the medical literature today.