Posterior dislocation of the atlas onto the axis without related fracture of the odontoid process is a very rare traumatic condition of which five cases have been previously reported. The authors present a sixth case in which management was different from the others. The patient was successfully treated by open reduction of the dislocation and C1-2 transarticular screw fixation. The rarity of the lesion, the differences in diagnostic studies, and the successful treatment by safe intraoperative reduction and fixation are factors of interest in this case.