Methods: A 62 year-old woman with intermittent pain, intermittent burning sensation and continuous numbness on the ulnar side of her left hand was admitted. Electromyographic examination showed an ulnar neuropathy in the Guyon's canal and an ipsilateral carpal tunnel syndrome.

Results: Exploration of the ulnar nerve in the Guyon's canal at the wrist showed that an 5 shaped tortuous ulnar artery compressed the ulnar nerve. Ulnar nerve decompression by ulnar artery transposition was performed and carpal ligament was partially excised. After the operation, pain and burning sensation were improved completely in a few hours, but numbness was continued.

Conclusion: Tortuous peripheral arteries are too rare causes of peripheral nerve entrapment syndromes. Resolution of intermittent pain and burning sensation by ulnar artery transposition in the presented case was suggested that the symptoms might be due to pulsatile pressure like in vascular compression of cranial nerves. Keywords : Peripheral nerve compression, ulnar nerve, Guyon's canal