Isolated injury to the extrahepatic biliary tree after blunt trauma is rare. The authors describe the case of a 17-year-old boy who suffered such an injury after falling over the handlebar of his motorcycle. Ultrasonography, computed tomography and abdominal paracentesis were used to make the diagnosis. At laparotomy there was a partial tear of the common bile duct at its junction with the cystic duct. A cholecystectomy was performed and a T tube inserted. The patient recovered without complication. The authors emphasize that only awareness of the condition and diagnostic confirmation by computed tomography and abdominal paracentesis can expedite the diagnosis and treatment. The choice of surgical repair must be individualized according to the clinical findings and the nature of the injury.