Penetrating head injuries are rare in children, with most injuries being accidental as a result of unsupervised use of sharp objects by young children. We present the case of a 4-year-old boy brought to our emergency department with a nail embedded through a wooden board and into his skull. The nail was determined to be entering the superior sagittal sinus through radiographic imaging. Thus, surgical removal of the nail was determined to be necessary. Inspection revealed a likely through-and-through injury to the sinus, and therefore, because sinus reconstruction was not deemed possible, the sinus was occluded with suture ties both in front and behind the nail before nail removal. Postoperatively, the patient did well and remained neurologically intact. Investigation for possible nonaccidental trauma was conducted. Although most commonly accidental in nature, nonaccidental penetrating traumas have been reported in both pediatric and adult populations. This patient did well after occlusion of his superior sagittal sinus at the coronal suture after penetrating injury by a nail. Penetrating injury in the pediatric population is predominantly thought to be accidental, but a high index of suspicion should be maintained for possible nonaccidental etiology.