Purpose : We evaluated clinical result of arthroscopic and open Bankart repair in anterior shoulder instability to identify factors iuluencing operative result and prognosis. Materials & Methods . We reviewed 24 patients of anterior shoulder instability treated with arthroscopic Bankart repair in 16 cases and open Bankart repair in 8 cases. Average age was 26 years old and involved in dominant arm in 15 cases. Patients were suffered instability for 3.1 years before operation and mean follow-up was 2 year 9 months ( 1 you 9 months -4year 10 months). Results : Post operative pain was subsided in 2 weeks in arthroscopic surgery and 3 weeks in open surgery. The final range of motion after arthroscopic repair were flekion in 168" , external rotation in 54" , and internal rotation in 79, and after open repair 168" ,49" , and 78 respectively. In arthroscopic surgery,2 cases (13%) were redislocated, and 4 cases(25%) showed mild instability. In open case,1 case (11%) showed mild instability. According to function- al result by Rowe grading scale, satisfactory results were 12case (76%) in arthroscopic repair and 7 cases (88%) in open cases. Conclusions Both arthroscopic or open Bankart could get good results in the treatment of anterior instability of shoulder. In arthroscopic repair, perioperative morbidity was lower than open repair, but it needs careful rehabilitation program to prevent redislocation and to return to sports activity.