An autopsy case of bilateral cortical necrosis of the kidneys in a 38‐year‐old unipara is presented. She underwent premature separation of the placenta at the 33rd gestational week which was followed by oliguria and anuria, and terminated in uremia on the 13th hospital day. Spasm of the renal arterial wall was highly suspected as the cause of the bilateral cortical necrosis of the kidneys, and the circumscribed intlmal thickening was thought to be due to the organization of microthrombi which had been produced at the time of the previous attacks of vascular spasm. Participation of predisposition in which the renal arterial tree is susceptible to vascular spasm was suspec