In two cases with a giant cell tumor of the axis, the mandible and tongue-splitting approach permitted excision of the tumor and anterior fusion of the spine from the atlas to the third cervical vertebra. With this approach, there is no need to extend or rotate the cervical spine during the operation. In addition, the operative field extends from the clivus to the fourth cervical vertebra, and safe and sufficient anterior decompression is possible. Although this approach has some disadvantages, contemporary techniques of intravenous hyperalimentation and postoperative respiratory management provide a solution to these problems. Thus, this approach should always be considered for patients requiring extensive anterior decompression of the craniovertebral junction or upper cervical spine.