Anterior interbody grafts are prone to displacement if there is posterior instability or gross deformity of the vertebral body. Twenty-one patients treated with anterior interbody fusion for cervical vertebral fractures and dislocations were studied. Twelve of the fractures were considered unstable preoperatively, and 50% of this group treated with anterior stabilization had graft migration postoperatively. If anterior fusion is used in unstable cervical fractures then posterior stabilization or complete bed rest with effective external stabilization (i.e., tongs or Halo-thoracic brace) for 4 weeks is mandatory. The other alternative is posterior stabilization before anterior decompression. In the presence of posterior instability, anterior interbody fusion alone cannot be recommended as the treatment of choice for cervical fractures.