Costello syndrome is characterised by dwarfism, unique cutaneous lesions, a distinct facial gestalt, and mental retardation. There have been no detailed reports of severe spinal deformities requiring surgical treatment as a complication of Costello syndrome. We report a case of a 10-year-old girl with progressive scoliosis associated with Costello syndrome. She underwent anterior release and posterior surgical correction and fusion from T5 to L2 using a third generation hook and rod system plus spinous process wiring. Congenital portal vein deficiency and coagulopathy were other major complications. At 15-month follow-up, the patient had good balance and no evidence of instrumentation failure.