We experienced an unusual complication of acute radial nerve palsy presenting as wrist drop after application of automated cycled blood pressure monitoring for 3 hours. A 19-year-old ASA physical status 1 female was scheduled to undergo nail removal, had been operated internal transport over the nail lengthening for fibular hemimelia. Blood pressure cuff was affixed to her right upper arm and worked automatically every 5 minute during surgery. One day after operation she complained of pain over the lower lateral aspect of the right upper arm and examination revealed zero power of the wrist and finger extensor muscles. Electromyelography (EMG) and nerve conduction velocity (NCV) revealed right radial neuropathy. She was discharged 20 days after operation with improvement of the right upper arm pain. After three months of physical therapy, the muscle power of wrist extensors reverted to completely normal and the muscle power of the finger extensors improved to fair.