ABSTRACT Scapular winging (SW) describes abnormal scapular mechanics from weak stabilizing muscles or altered neural innervation. While electromyography (EMG) helps differentiate between myo‐ or neuropathic SW etiologies and determine the extent of muscle involvement, pediatric EMG may be limited due to the high risk of surrounding structures, small body habitus, and pain tolerance. Herein is a case of pediatric SW following anterior neck lymphadenopathy resection in which EMG was limited. Neuromuscular ultrasound (NMUS) showed asymmetric trapezius thinning and hyperechogenicity, revealing more expansive involvement than was previously known. NMUS is a painless, validated tool to augment the diagnostic capability of EMG and clarify the extent of neuromuscular involvement in SW from both a prognostic and rehabilitation point of view.