Purpose: The aim of our study was to evaluate thoracic vertebrae rotation in patients with pectusexcavatum. Moreover, we wanted to assess the prevalence, the severity and relationship between pectusexcavatum and adolescent idiopathic scoliosis (AIS).Methods: We performed retrospective analysis of 82 preoperative chest CT in children with pectusexcavatum performed between January 2008 and December 2011. For each patient Haller Index and Cobbangle was measured. To evaluate the severity of thoracic scoliosis we measured vertebral rotation for Th8and for vertebra at the level of highest chest deformation using Aaro-Dahlborn method.Results: From the group of 54 patients with pectus excavatum enrolled in the study AIS was diagnosed in8 patients (14,81%). In patients with symmetric deformation, Th8 rotation was found in 21 patients; therotation of the apical vertebra was found in 20 patients. In patients with asymmetric deformation Th8rotation was found in 10 patients; the rotation of the apical vertebra was found in 8 patients.Conclusions: 1. We have conŞrmed the higher prevalence of pectus excavatum in boys; 2. We have founda signiŞcant relationship between pectus excavatum and adolescent idiopathic scoliosis; 3. We haveshown that deformation of the anterior chest wall enforces rotation of the thoracic spine; 4. We haven'tfound the relationship between the severity of the chest deformity (HI measured) and severity of AIS(Cobb angle measured); 5. We have shown a signiŞcant association between HI measured and rotation ofthoracic vertebra at the level of highest chest deformation (apical vertebra) in symmetric pectusexcavatum.Level of evidence: Level IV, Diagnostic study.© 2017 Turkish Association of Orthopaedics and Traumatology. Publishing services by Elsevier B.V. This isan open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).