Rotator cuff tears are a common cause of shoulder pain and dysfunction. Causes of posterior superior rotator cuff (supraspinatus, infraspinatus, and teres minor) tears include severe trauma, repeated microtrauma, external impingement, internal impingement, and degeneration of rotator cuff tissue. Rotator cuff tears often coexist with other disorders, such as frozen shoulder, osteoarthritis, and chronic instability, and their diagnosis should be analyzed by combining clinical features and ancillary examinations such as X-ray, ultrasound, and MRI. The treatment of rotator cuff tears includes non-surgical treatment and surgical treatment. Non-surgical treatment includes rest, ice, physiotherapy, oral anti-inflammatory and pain-relieving drugs, rotator cuff muscle training, and subacromial gap closure. Surgical treatment of rotator cuff tears includes traditional incision surgery and arthroscopic rotator cuff repair.