OBJECTIVE Penetrating injuries of the cranium and spine are frequent to the civilian neurosurgical practice. Although a variety of unusual objects have been reported, to our knowledge, there has never been a craniocerebral or spinal injury caused by a fish. An unusual case of transoral penetration of the foramen magnum by a billed fish is described. The history, radiographic studies, and treatment are presented. METHODS A fisherman struck by a jumping fish initially presented with severe neck pain and stiffness, bleeding from the mouth, and a laceration in the right posterior pharynx. A computed tomographic scan of the cervical spine revealed a wedge-shaped, hyperdense object extending from the posterior pharynx into the spinal canal between the atlas and the occiput. Because of the time factor involved, the fisherman was brought directly to surgery for transoral removal of the object. METHODS The patient was placed under general anesthesia, and with a tonsillar retractor, a kipner, and hand-held retractors, the object was visualized and identified as a fish bill. Further dissection above the anterior aspect of the atlas permitted removal of the object by means of a grabber from an arthroscopic set. No expression of cerebrospinal fluid was noted, and a Penrose drain was placed. CONCLUSIONS The patient was treated under the assumption that penetrating foreign objects in continuity with the cerebrospinal fluid space and the outside environment should be removed as soon as possible. The patient was provided appropriate antibiotics to treat potential infection of normal pharyngeal flora and organisms unique to the marine environment. The patient recovered and did not experience any residual neurological deficit.