Introduction. Spinal muscular atrophy (SMA) is a group of hereditary diseases that manifests in weakness and flaccid paresis, marked mostly in lower limbs and proximal rather than distal muscle groups. Three clinical types may be distinguished depending on the level of muscle involvement. Spine deformity, present in all non-ambulatory patients poses the greatest orthopaedic challenge. Scoliosis often called “collapsing scoliosis” hampers or totally impairs independent sitting in this way decreasing patients function. Treatment of choice is surgical that leads to deformity correction, prevents further curve progression and facilitates independent sitting. Aim of paper. Aim of paper is radiological evaluation of results of surgical treatment of spine deformity in patients with SMA type 2 and SMA type 3a all treated with the same Galvsetone-Luque posterior fusion surgical technique. The study is to establish the optimal criteria for surgical treatment. Material and methods. Among 173 patients with SMA diagnosis 45 fulfilled the inclusion criteria. The minimal follow-up period was 5 years, and mean follow-up was 6.9 years (5 – 15 years). Clinical data, preoperatively and perioperatively was evaluated: age of SMA diagnosis, age of scoliosis onset, perioperative complications. Moreover radiological data pre- and postoperatively was assessed. Results. Age at surgery in the study group was mean 11.4 years. Achieved correction after surgery was mean 49% and 41.9% in the final follow-up. Evaluation of radiological data revealed that better correction was achieved in younger patients with smaller initial curve. Above that loss of correction was significantly lower in the more mild form of SMA. Number of postoperative complications did not correlate with the preoperative pulmonary function. Conclusion. Treatment of spinal deformities in SMA patients is justified; achieved correction is approximately 40% with minimal loss during follow-up. Surgical treatment should be introduced early as possible, in patients with curves less than 80° and younger than 11 years. Those two factors significantly influence the final outcome.