BACKGROUND: This study measured the rate of adrenal insufficiency among rotator cuff tear patients, and determined the roles of steroid treatment and herbal medicine as specific risk factors of adrenal insufficiency. METHODS: We prospectively evaluated the 53 patients who agreed to participate in the study and underwent arthroscopic rotator cuff repair due to a chronic full-thickness tear from March 2012 to September 2013. The diagnosis of adrenal insufficieny was made by rapid adrenocortical hormone test before the operation. We collected information regarding their history of steroid and herbal medicine treatment within the last 12 months. RESULTS: The rate of adrenal insufficiency among the rotator cuff tear patients in our study was 18.9% (10 of 53 patients). Steroid treatment (p=0.034), frequency of local steroid injection (p=0.008), and herbal medicine treatment (p=0.02) showed significant association with the risk of adrenal insufficiency. CONCLUSIONS: In this study, careful taking of a patient's medical history, such as the use of steroids and herbal medicine, is important when investigating adrenal function before surgery.