There are many cases of peripheral nerve injury by patient position during perioperative period. It is thought to occur by compression or traction and ischemia of nerves. We had an experience that injury of common peroneal nerve below fibular head occurred by lithotomy positon during operation for urethral stricture under spinal anesthesia. Because the nerve injury can be reduced by some caution, it is important to be well-informed about and predict the risk of peripheral neuropathy during lithotomy position.