This study examined the dynamic stiffness and failure tolerance of human adult lower cervical spine specimens subjected to lateral bending moments. A total of 9 cadaver cervical spines (65.0 ± 4.2 years) were dissected into 27 functional spinal units (C3-C4, C5-C6, and C7-T1) and tested to failure in a custom bending fixture within a MTS servohydraulic test frame. The average applied angular displacement rate was 10.8 ± 2.9 rads/sec. Average dynamic stiffness in lateral bending was 151 ± 44 N-m/rad, and the average failure moment was 26.3 ± 5.5 N-m. The lateral bending tolerance was similar to those reported by Nightingale et al. for the human adult lower cervical spine in flexion (17.4 N-m) and extension (21.2 N-m).