The hypothenar hammer syndrome is an uncommon lesion of the ulnar artery caused by repetitive trauma to the ulnar portion of the hand. It characteristically occurs in the dominant hand of middle-aged craftsmen, but also in athletes practising various types of sports. We present a retrospective study of nine patients between 1988 and 1999. The follow-up ranged from 1 to 10 years. We recommend surgical treatment, by resection of the involved arterial segment and revascularization either by direct anastomosis or by means of a venous interpositional graft.