Nonoperative management with close observation represents the standard of care for blunt liver injury, unless vital signs deteriorate or an associated injury requires emergency operation. Injuries of the biliary tract remain important concomitant lesions following liver trauma. Posttraumatic extraductal biliary collections or biliomas are rare complications of blunt abdominal traumas and only a few cases have been reported in the pediatric age group. We report a 5-year-old boy who suffered from blunt abdominal trauma that resulted in liver laceration and, eventually, bilioma formation. The patient was managed nonoperatively for liver injury. The diagnosis was confirmed by computed tomography (CF)-guided needle aspiration and percutaneous catheter drainage, which also allowed nonoperative management. The patient was symptom-free with normal liver function tests and a normal liver appearance on ultrasound examination six months after the accident. The possibility of missed bile duct injury should be considered when nonoperative management is used and close observation of the patient is necessary over a prolonged period.