5 patients requiring posterior fusion for the fracture-dislocation of cervical spine were treated with Halifax interlaminar clamps for internal fixation. 4 patients had unilateral and another patient had bilateral facet dislocation. Fusion was at the C3-4 level in 1 case, the C4-5 level in 3, and the C6-7 level in 1. Facetectomy for reduction at the locked facet was required in 3 cases. Autogenous iliac bone grafting was performed in 1 case with bilateral facet dislocation. Satisfactory stabilization without complication was achieved in all patients. Halifax interlaminar clamps are effective for the posterior stabilization of traumatic lower cervical spinal instability.