Background: We determined whether the cardiovascular responses to endotracheal intubation change as a function of the time elapsed after injury and the level of injury in patients with spinal cord injury. Methods: One-hundred-eighty six patients with complete cord injury were grouped into 3 according to the level of injury: high- (T1？T4, n = 34), mid- (T5？T10, n = 47) and low paraplegics (＜ T10, n = 105). They were further divided into 5 according to the time elapsed since injury: ＜ 4 wks, 4 wks？1 yr, 1？5 yrs, 5？10 yrs, and ＞ 10 yrs. Twenty-five patients with no cord injury served as controls. Systolic arterial blood pressure (SAP), heart rate (HR), and plasma catecholamine concentrations were measured.