OBJECTIVE We determined whether symptoms of autonomic dysreflexia correlated with elevations in blood pressure in men with spinal cord injuries. METHODS During a routine yearly urodynamic evaluation 45 consecutive men with complete spinal cord injuries above T6 underwent simultaneous monitoring of blood pressure and symptoms of autonomic dysreflexia. Those with systolic blood pressure of greater than 160 mm. Hg or diastolic blood pressure of greater than 90 mm. Hg during voiding were assigned to the hypertensive group. During voiding 35 men (78%) had significant hypertension. RESULTS Before voiding there was no statistical difference in mean systolic blood pressure between men with and without hypertension (117 versus 110 mm. Hg, p = 0.28). During uninhibited contractions and voiding mean systolic blood pressure of the normotensive group (131 mm. Hg) versus the hypertensive group (169 mm. Hg) was statistically significant (p < 0.0001). Of the 35 hypertensive patients 15 (43%) had no symptoms of autonomic dysreflexia. There was no correlation of autonomic dysreflexia with length of injury, maximum voiding pressure or bladder capacity (p = 0.59, 0.85 and 0.34, respectively). CONCLUSIONS Urodynamics are helpful to detect symptomatic and asymptomatic autonomic dysreflexia. Significant elevations in blood pressure can occur without the symptoms of autonomic dysreflexia.