Introduction: In teens, athletes, in general, have been found to have shoulder pain and or winging scapula resulting from long thoracic or spinal accessory nerve injuries. Accident (fall) and stretch injuries due to overuse and poor sports techniques mainly cause these injuries that affect their upper extremity movements and functions. Here, we report a significant improvement in scapula winging and shoulder active range of motion in 16 teen patients after long thoracic nerve decompression and neurolysis. Patients and Methods: This was a retrospective study of 16 teen patients who had severe winging scapula and poor shoulder movements and function. Therefore, they underwent decompression and neurolysis of long thoracic nerve with us, between 2005 and 2016. The average patient age was 17 years (range, 14-19 years). These patients had been suffering from paralysis for an average of 15 months (range, 2-48 months). All patients underwent a preoperative electromyographic assessment in addition to clinical evaluation to confirm the long thoracic nerve injury. Results: Scapula winging was severe in 10 of 16 patients (63%), moderate in 2 patients (12%), and mild in 4 patients (25%) in our present study. Mean shoulder abduction (128°) and flexion (138°) were poor preoperatively. Shoulder abduction and flexion improved to 180° in 15 patients (94%) and good (120°) in 1 patient (6%) at least 2 months after surgery. In 11 patients (69%), the winged scapula was completely corrected postsurgically and it was less prominent in other 5 patients. Conclusion: Long thoracic nerve decompression and neurolysis significantly improved scapular winging in all 16 teen patients in our present study, producing “excellent” shoulder movements in 15 patients (94%) and “good” result in 1 patient (6%).