Objective To determine if patients with traumatic, unidirectional recurrent anterior shoulder instability who have labral repair plus arthroscopic capsular shrinkage have better outcomes than those with labral repair alone. Methods This retrospective clinical study had a case controlled cohort design. 72 patients who met the inclusion criteria had the arthroscopic anterior shoulder stabilization by the same surgeon with Suretac Ⅱ tissue tacks (Suretac group, n=32) during 1996-1999 or with the same Suretac Ⅱ tissue tacks plus arthroscopic radiofrequency(Suretac plus shrinkage group, n= 40) from 1999 to 2002. The postoperative rehabilitation protocol for these two groups was identical. Standardized patient-determined and examiner-determined outcome measures were obtained pre-operatively, and at 3, 6, 12, and 24 months after operation, respectively. Results 66 were available at the final follow-up in this study, including 28 patients treated with the Suretac stabilization and 38 patients treated with the Suretac plus radiofrequency shrinkage, with the average duration of 58 and 30 months, respectively. All patients had a Bankart lesion. Both groups were matched for sex, age, level of pre-operative activity in work and sports, time from first injury to surgery and the number of tissue tacks used. Both groups had similar results with respect to patient-determined and examiner-determined outcome measures. The only adverse outcome was recurrent instability. In the Suretac group, 5 patients recurred dislocation, 1 recurred subluxation. In the group of Suretac plus shrinkage, 6 recurred dislocation, 2 recurred subluxation. Most re-dislocations and subluxation occurred during the 6th-24th months postoperatively and were subject to sports injury. Kaplan-Meier analysis for time to re-dislocation or re-subluxation as the criterion standard showed no differences in the rate of instability recurrence between the two groups. Conclusion Arthroscopic thermal capsulorrhaphy neither improved nor impaired the outcomes of arthroscopic labral repair with biodegradable tacks in patients with primary anterior shoulder instability.