Several congenital anomalies of the odontoid process have been described in the literature. Malformations of the dens include aplasia, hypoplasia, duplication, condylicus tertius, os terminale (os avis) and os odontoideum. Os odontoideum is the most common anomaly of the odontoid. However, there is insufficient evidence to support treatment standards and guidelines for patients with os odontoideum in the literature. In this article a patient with os odontoideum who underwent two separate operations due to spinal cord compression during cervical motion is presented and the surgical treatment modalities are discussed.