Segmental screw fixation is a useful procedure for the surgical treatment of atlantoaxial subluxation. Currently, C1 lateral mass screws and C2 pedicle screws are the standard screws used in this procedure. However, the C2 pedicle screw can cause serious complications such as vertebral artery injury. Recently we suggested a new trajectory for the C2 screw, the subarticular screw, which has a lower probability of vertebral artery injury compared with the pedicle screw, based on a study using 1 mm-sliced CT scan images and simulation software. We report the first case of segmental screw fixation using C2 subarticular screws along with C1 lateral mass screws. The patient had atlantoaxial subluxation and myelopathy and showed satisfactory results after surgery.