Nowadays false aneurysms have become an important part of the workload of a vascular surgeon as a result of the increasing number of iatrogenic arterial trauma occurring during diagnostic and therapeutic procedures requiring puncture or exposure of blood vessels. A case of a false aneurysm in the ulnar artery caused by a simple syringe needle during an intravenous cannulation is reported. The clinical symptoms and details of the diagnostic procedure based upon color-Doppler and angiography are examined. The vascular operation consisted in proximal and distal arterial control, resection of the aneurysm and end-to-end anastomosis. After surgical treatment the patient experienced an excellent anatomic and functional recovery.