OBJECTIVE: To investigate the effect of extracorporeal shock wave therapy (ESWT) on muscle spasticity of elbow and wrist affected by stroke. Methods: We studied 21 patients affected by stroke with spasticity in upper limbs. The neurological status of the stroke patients were evaluated by K-NIHSS and the evaluation of efficacy on the upper limb spasticity were based on modified Ashworth scale (MAS), modified Tardieu scale (MTS), and active elevation of upper limb. Treatment was performed 1 session/week, total 3 sessions in each patient. Patients were evaluated at baseline and 4 weeks after treatment using MAS of elbow flexor and active elevation of upper limb. Patients were monitored at baseline, after sham stimulation, and at 1, 4 weeks after ESWT using MTS of elbow flexor and wrist pronator. RESULTS: After ESWT, patients showed significant improvement in muscle tone of elbow flexor and wrist pronator after the 1st and 4th weeks compared with baseline and sham stimulation (p<0.001). The active elevation of hemiplegic upper limb was significantly increased (p<0.05). CONCLUSION: We suggest the ESWT could be a useful treatment method on upper limb spasticity in the patients of stroke. Further studies with a larger group of patients are warranted.