The aim of this report is to describe the management of a severe spinal deformity in an adolescent with facioscapulohumeral dystrophy (FSHD) and review the available literature on the topic./r/nA 14-year-old patient with a genetically confirmed diagnosis of FSHD was evaluated for right thoracolumbar scoliosis (TL) and severe lumbar hyperlordosis. Spinal radiographs showed a right-sided curve of 32° and in the sagittal plane a lordotic curve T10-S1 -143°, TL junction -51.6°, LL -115°, pelvic incidence (PI) 25.5°, pelvic tilt 63.3°, PI-LL mismatch -90°, and a sagittal imbalance of -146 mm. An MRI scan evidenced atrophy of the paraspinal muscles. An instrumental gait analysis revealed significant pelvic anteversion associated with hip flexion and mild equinus. During follow-up, the patient developed a progressive inability to walk and difficulty sitting along with respiratory compromise and pain./r/nAt the age of 16 years, a posterior T2-iliac spinal fusion was performed using pedicle screws and four iliac anchors, with a 4-rod system placed at the lumbopelvic level. Significant correction of the hyperlordosis, the PI-LL mismatch, and sagittal imbalance was achieved, and the patient improved her sitting capacity, quality of life (QoL) and self-esteem and reported a decreased perception of disability at 2-year follow-up./r/nThis is the first published case of spinal deformity secondary to FSHD to use gait analysis to supplement the decision of optimal timing for surgery, and the second published case of spine surgery in a pediatric patient. Although spinal fusion surgery is controversial in ambulatory FSHD patients with extensive deformity, when ambulation is impaired, surgery improves function, prevents progression, and restores sagittal balance, increasing patient’s QoL.