Background <p>Pulmonary hydatid cyst disease is a common zoonotic infection, especially in agricultural and livestock communities. Thoracotomy is an important surgical procedure in the treatment of pulmonary hydatid cysts in children. However, the development of a spinal deformity is one of the long-term musculoskeletal complications of this procedure. The aim of this study was to evaluate the incidence, risk factors and clinical outcomes of spinal deformity in pediatric patients after thoracotomy.</p> Methods <p>Between 2008 and 2022, 116 pediatric patients who underwent thoracotomy for pulmonary hydatid disease and met the study criteria were retrospectively reviewed. Age, sex, side of surgery, pre- and postoperative spinal radiographs, presence of spinal deformity and Cobb angles were measured.</p> Results <p>Spinal deformities developed in 57.8% of 116 patients after thoracotomy. The risk of spinal deformity increases with decreasing age at surgery. The side of the thoracotomy can influence the direction of the apex of the spinal deformity. However, sex had no significant effect on the development of spinal deformity.</p> Conclusions <p>Children with pulmonary hydatid cyst disease are at high risk of developing spinal deformity after thoracotomy, and this risk is greater in younger patients. This study emphasises the importance of multidisciplinary approaches in the prevention and management of spinal deformity.</p>