o investigate the mechanisms, diagnosis, and surgical procedures of simultaneous lesions of the rotator cuff and the axillary nerve.[Methods] Between July 2013 and June 2016, five patients with rotator cuff tear associated with axillary nerve injury were treated in Affiliated Hospital of Taishan Medical College. There were 3 males and 2 females with a mean age of 33.6 years (range, 18～42 years). The reasons of injury were accident damaging in 1 case, stretching injury in 1 case, falling injury from height in 1case, and 2 cases in explicity with a mean disease duration of 16.6 days (range, 5～33 days). 3 patients accepted arthroscopic rotator cuff repairing, and 2 cases received conservative treatment.All patients accepted nutrition nerve treatment and physical therapy. [Results] All incisions healed by first intention without complication. All the 5 patients were followed up 16 to 20 months (mean, 17.8 months). The function, muscle strength, and sensation of the shoulder were improved obviously except 1 case. The shoulder Malleet score was (9.20 ± 2.39) and was signicantly better than preoperative score (t= —3.207, P=0.033). The VAS score was (2.8 ± 0.84) and was signicantly better than preoperative score (t=12.829, P=0.002). The functional score of brachial plexus was(13.20±1.48) and was signicantly higher than preoperative score(t=—13.416,P=0.0002). [Conclusion] It is difficult to diagnose lesions of the rotator cuff and the axillary nerve simultaneously; orthopedists should pay attention to possible patients to avoid missed diagnosis and diagnostic errors. Nerve nutrition, physical therapy, and arthroscopic rotator cuff repair can achieve good effectiveness.