Neurologic and abdominal complications can occur in the postoperative period of aortic coarctation repair, ischemia being the pathogenic factor most likely to be involved. This study was designed to evaluate the extent of the hemodynamic changes proximal and distal to the coarctation at the time of cross-clamping, as well as the effects of pentolinium and isoproterenol upon the hemodynamic changes. Included in the study were 17 patients with adult type coarctations who had dual hemodynamic monitoring. During cross-clamping, there was an increase in the gradient between proximal and distal pressures, with severe distal hypotension (< 50 mm Hg) occurring in six patients. Isoproterenol corrected the hypotension in five patients, but the sixth required a surgical shunt. Pentolinium was effective for the treatment of proximal hypertension; however, it also decreased distal pressure. The ligation of collateral vessels was associated with a decrease in distal pressures as well. During cross-clamping, pentolinium was useful for the management of proximal hypertension and isoproterenol increased the distal pressures in some of the patients who presented distal hypotension. However, because of the difficulties in predicting the individual response, their administration would be best guided by dual pressure monitoring. It is postulated that the recognition and proper treatment of distal hypotension may be an important factor in the prophylaxis of postoperative complications.