A 35-year old man with coldness, paleness, numbness, and pain at Dig. IV of the left hand comes to the consultation. The Allen test is pathological, the angiography shows an occlusion at the length of 4 cm of the Arteria ulnaris beginning at the Hamulus ossis hamati. After therapy with prostaglandin E1, aspirin 100 mg for 10 days and a smoking stop, the symptom disappeared at the re-consultation after 10 days.