Aneurysms of the hand can occur following blunt trauma to those portions of the radial and ulnar arteries unprotected by the palmar fascia. The presenting symptom is a gradually enlarging mass that may be associated with pain and vascular insufficiency. We report 11 aneurysms: five ulnar, four radial, one dorsal interosseous, and one perineural artery. Both true and false aneurysms occurred, and both often followed blunt trauma. The aneurysms were present for periods ranging from two weeks to six months. Treatment was resection with attempted reanastomosis of the artery. In six of the aneurysms it was possible to accomplish reanastomosis with reconstitution of flow. It is our opinion that vascular anatomy should be restored to as near normal as possible to prevent later intolerance to cold and to work with the hand.