This case report details the clinical presentation and surgical management of a neonate with idiopathic perforation of the biliary tract. A three-day-old baby girl presented with a right-upper-quadrant mass and signs of peritonitis following a prolonged, difficult vaginal delivery. At surgery, she was found to have a perforation at the junction of the cystic and common bile duct. Simple drainage of the right upper quadrant was performed, and the patient recovered uneventfully. Early presentation and the nature of delivery suggests the possibility of birth trauma as an etiological factor in this condition.