Carpal tunnel syndrome is the most common peripheral nerve entrapment syndrome that characterized by pain, especially in night, sensory disturbance in median nerve dermatome of the hand, and thenar muscle atrophy. Open decompression was a treatment of choice, when operative intervention is necessary. But, endoscopic or percutaneous decompression is introduced recently. Authors analyzed 21 cases of open decompression and 22 cases of percutaneous decompression and they could be follow up over 6 months at Dept. of Orthopedics, Chonnam University Hospital from June 1990 to January 1995. The results are as follows. 1. There were no difference in age, sex, lesion side, symptoms duration until operation, etiology and occupation between percutaneous and open decompression. 2. There were excellent or good results in clinical symptom in 19 cases(90%) of open procedures and 19 cases(86%) of percutaneous procedure and more rapid relief of the pain, and grip power in percutaneous procedure than open procedure. 3. The EMG, recorded at 1 week, 4 weeks, 3 months and 6 months after operation, revealed improvement in sensory than motor function. There was more rapid recovery in percutaneous procedure than open procedure especially latency and amplitude of sensory nerve. There were 2 cases in open procedure and 3 cases in percutaneous procedure who did not respond to treatment. As a result, percutaneous procedure was more simple and rapid recovery than open procedure in clinical progressions and EMG reports, but recovery rate of symptomatic relief was similar. Therefore percutaneous procedure is thought to be more reasonable method in the treatment of carpal tunnel syndrome if surgical intervention is indicated.