A 16-year-old girl with primary oxalosis type I presented with progressive claudication soon after being treated with chronic intermittent hemodialysis. Arterial insufficiency of the lower limbs was confirmed clinically (purple discoloration of the skin and absence of arterial pulses) and with Doppler sonography. The arteriogram showed diffuse and symmetric narrowing with smooth vessel walls. Treatment with sodium nitroprusside had a spectacular effect; nifedipine was less effective. Renal transplantation with the father's kidney resulted in a rapid, complete and sustained reversal of the ischemic features. Magnesium withdrawal is assumed to be a pathogenic factor of the vascular spasm in this patient.