A 50-year-old man suffered from sudden onset of paraplegia, sensory impairment of the lower extremities and difficulty urinating. These symptoms spontaneously resolved, and he was able to walk again within 10 days. After 2 months' observation, he experienced a relapse with identical symptoms. Neurological examination revealed paraplegia, hypalgesia and hypesthesia in the lower extremities and difficulty urinating. Position and vibration senses were preserved in the extremities. Knee jerk was mildly hyperreflexic on the left, but pathological reflexes were not present. He had such risk factors for arteriosclerosis as diabetes mellitus, hypercholesterolemia and smoking. Although antinuclear antibodies were negative, he repeatedly showed high anticardiolipin antibody titers. MRI showed a T2-hyperintense lesion of the anterior portion of the spinal cord at Th9-10 levels. Neither arteriovenous malformation nor fistula was found on MR angiography. Abdominal CT revealed no abnormality in the descending aorta. Cervical ultrasonogram showed arterioslerotic lesions on the right common carotid artery. This is the first report of recurrent spinal cord infarction in an adult patient associated with primary antiphospholipid syndrome. Recurrence of the spinal cord infarction in this case may have been facilitated by the presence of risk factors for arteriosclerosis.