The purpose of this study was to evaluate the effectiveness of the transaxillary subcutaneous endoscopic sternocleidomastoid muscle division for treatment of persistent torticollis. Traditionally persistent sternomastoid torticollis is treated with a neck incision which results in a neck scar. We report our technique of transaxillary subcutaneouscopic sternocleidomastoid (TASS) division for treatment of persistent torticollis which avoids a neck scar and provides a better view of the neck structures. A 10-year-old girl presented to the clinic for the first time with a history of right sided torticollis. Contralateral (left) side neck rotation and extension were extremely limited. She was able to flex and rotate her neck slightly to the same side. A tough fibrous cord was felt on palpation of her right sternomastoid which was limiting her neck motion. Her neck position was flexed and rotated to the right at rest. The right sternocleidomastoid muscle was divided using the transaxillary subcutaneouscopic technique. The patient tolerated the procedure very well with full range of motion (was able to flex and extend the neck fully and also able to move it side to side [rotation] to the full extent on both sides) of her neck and had good cosmetic results with almost invisible scars hidden in the axilla. Finally, we concluded that the transaxillary subcutaneouscopic sternocleidomastoid muscle division is a good surgical technique for treatment of persistent torticollis in children.