In subjects with spinal cord injury (SCI) a restrictive ventilatory impairment has been well described. Despite numerous studies of pulmonary function in patients with SCI, evidence of an obstructive component of respiratory dysfunction as a result of paralysis has not been observed in this population. We performed spirometry in 34 patients with cervical SCI before and after administration of an inhaled bronchodilator. Significant improvement in flow rate was demonstrated in 14 (41%) subjects. Our results suggest that transection of the cervical spine may result in obstruction to air flow, possibly due to interruption of the sympathetic innervation of the lung with resultant unopposed parasympathetic tone producing bronchoconstriction.