Eleven cases of injury of the superficial radial nerve on the wrist joint, caused by intravenous injection of a needle. Paralysis occurred immediately after injection of a needle into the cephalic vein of the wrist joint, which was immediately recognized by the patients themselves. Six patients who had only sensory disturbance without causalgia were subjected to follow-up observation; 5 patients with causalgia were administered with steroid infiltration injection 3 to 5 times. Of the latter 5 patients, one patient underwent surgery because the steroid infiltration injection showed no effects. Four patients (36.4%) completely recovered within three months, while 7 patients (63.6%) continued to show nervous symptoms. We concluded that intravenous injection of a needle should be performed at the wrist joint only when it is inevitable.