From January 1982 to September 1987, ten diagnosed cases of biliary ascariasis were collected among 8,160 cases who were admitted for biliary tract diseases in our hospital. It represented an incidence of 0.12% in our hospital. In our series, the patients' ages ranged from 33 to 68 years old, with a female predominances. The clinical impression on admission were those of biliary tract stone, infection or pancreatitis. Signs and symptoms of biliary ascariasis were abdominal pain, fever, jaundice, vomiting of round worms and distended gallbladder. Laboratory findings disclosed leukocytosis, mildly elevated alkaline phosphatase, transaminase and bilirubin. There was a relatively high incidence of positive bile culture for bacteria. The reliable diagnostic tools for biliary ascariasis were abdominal real-time ultrasonography and endoscopic retrograde cholangiopancreatography (ERCP). They yielded a diagnostic rate of 40% and 87.5% respectively in our series. The principles of management of biliary ascariasis were conservative treatments including intravenous fluids, nasogastric decompression, antibiotics and antihelmintic agents. Other treatments that were also tried included endoscopic removal of round worms through a T-tube, or nasobiliary drainage. Surgery was considered when there were signs of complications, such as uncontrolled sepsis or suppurative cholangitis. The prognosis of biliary ascariasis was good if patients were diagnosed and treated properly. Regular follow-up with antihelmintic agents is also recommended to avoid reinfection.