Many etiologies have been proposed for renal artery stenosis following renal transplantation. Incorrect operative technique is the most frequent cause, but the condition is often due to vascular parietal lesions resulting from traction on the vessels during removal of kidneys, which causes dislocation of arterial parietal structures. Such traction is inevitable if kidneys are removed separately due to difficulties arising during deep mobilization of the kidneys. Furthermore, this technique involves direct flushing into the renal artery, and this may cause damage to the intima due to the canula. Canula and traction are the major causes of stenosis. The authors present their own cases and propose that kidneys be removed "en bloc". This is the only way to prevent traction on vessels, and it permits flushing through the aorta for cooling.