Introduction. The most frequent type of scoliosis, i.e. of lateral spinal curvature, is idiopathic scoliosis. Its origin has not been officially determined even though it constitutes ca. 80% of all scoliosis cases. There are numerous etiopathological hypotheses in idiopathic scoliosis but none of them has been fully confirmed yet. One of the hypotheses describes the process of its origin as initiated by an asymmetrical configuration of the pelvic bones. The aim of the present study is an attempt to determine whether it is possible to describe any relationship between an asymmetrical configuration of the pelvic bones and a change in the position of the spine in the patient’s sagittal plane. Material and methods. The study was conducted on a set of data (18,071 cases) collected while evaluating the correctness of children’s posture over the last 15 years. The examination used the palpation method, generally applied in medicine. The examination included numerous parameters; for the purpose of the study, however, only two features (variables) were taken into account, namely the difference in the position of the hip bones (its extent and type) and the size and shape of the patient’s scoliosis. The data were analysed with Statistica 9.0 software. Results. Data mining yielded a result in the form of a decision tree obtained with the random forest method. Conclusions. The study and data mining based on a representative sample of cases made it possible to confirm a relationship between the size and direction of the pelvic asymmetry and the shape and size of the scoliosis.