The effects of cervical spinal adjustments delivered bilaterally either to the upper cervical region (C2-C3) or to the lower cervical region (C6-C7), were compared in groups of asymptomatic subjects exhibiting goniometrically verified left-right rotational or left-right lateral-flexion passive end-range asymmetries of greater than 10 degrees. Goniometric evaluation both prior to, and again within 30 min following treatments revealed that lower cervical adjustments were far more effective for the amelioration of lateral-flexion asymmetries than were upper cervical ones, whereas upper cervical adjustments were found to be more effective for the amelioration of rotational asymmetries than those delivered to the lower cervical region. These results are consistent with the view that passive movement restriction exhibited along the rotational axis is attributable to factors related primarily to the upper cervical region, whereas restrictions of passive movement along the lateral axis are more attributable to factors related to the lower cervical region. Further support for the regional independence of these axis-specific relationships is provided by similar results obtained in groups of subjects who happened to exhibit both rotational as well as lateral-flexion asymmetries of greater than 10 degrees on the day of the experiment.