Objective To explore the mid-term effectiveness of arthroscopic “mini incision” transtendon repair for partial articular-sided supraspinatus tendon avulsion (PASTA) lesion. Methods A clinical data of 39 patients with PASTA lesions, who underwent the arthroscopic “mini incision” transtendon repair and met the selected criteria between May 2017 and April 2021, was retrospectively analyzed. There were 13 males and 26 females, with an average age of 63.7 years (range, 43-76 years). Nine patients underwent trauma history, and no obvious inducement was found in the other 30 patients. The main clinical symptom was shoulder pain with positive hug resistance test. The interval from symptom onset to operation was 3-21 months (mean, 8.3 months). The visual analogue scale (VAS) score, University of California Los Angeles (UCLA) shoulder score, American Association of Shoulder and Elbow Surgeons (ASES) score and shoulder range of motion (ROM) of forward flexion, abduction, and external rotation were used to evaluate shoulder function. MRI was performed to assess the structural integrity and tension of reattached tendon. Patient satisfactions were calculated at last follow-up. Results All incisions healed by first intention with no complications such as incision infection or nerve injury. All patients were followed up 24-71 months (mean, 46.9 months). The VAS, UCLA, and ASES scores significantly improved at 24 months after operation when compared with preoperative ones (P<0.05). The ROMs of forward flexion and external rotation of the shoulder joint significantly increased at 3 and 24 months, and further increased at 24 months compared to 3 months, with significant differences (P<0.05). However, the ROM of abduction of the shoulder joint at 3 months did not significantly improve compared with that before operation (P>0.05), and it was significantly greater at 24 months than before operation and at 3 months after operation (P<0.05). At last follow-up, the patients were very satisfied with the effectiveness in 30 cases (76.9%), satisfied in 5 cases (12.8%), and dissatisfied in 4 cases (10.3%). At 6 months after operation, 31 patients underwent reviews of MRI scans, of which 28 patients possessed intact structural integrity, good tendon tension and tendon healing, and 3 patients underwent tendon re-tear. ConclusionArthroscopic “mini incision” transtendon repair in treatment of PASTA lesion could obtain satisfying mid-term effectiveness with low risk of tendon re-tear.