Background. In children with spondylolisthesis, there are still unexplained aspects in the relationship of the degree of displacement of the L5 vertebra with the severity of the clinical picture and neurological disorders. At the same time, aspects of the mutual aggravating influence of the indicated spinal disorder on the condition of the feet have not been studied. Therefore, the problem of identifying disorder of foot function in children with spinal spondylolisthesis of the L5 vertebra is relevant.Aim of the study — to evaluate the deviations in parameters of the transverse and longitudinal arches of feet in children suffering from severe spondylolisthesis of the L5 vertebra.Materials and Methods. In the period from 2016 to 2018, 12 children aged 14.1 y.o. [12,7; 15,5] were examined with spondylolisthesis of the L5 vertebral body of grade III-IV, accompanied by stenosis of the spinal canal at the same level and by compression of the roots of the spinal cord. Imaging diagnostics included multispiral computed tomography (MSCT) and magnetic resonance imaging (MRI). To estimate the function of the feet, double-bearing and single-bearing plantography was used. The data for the control group included only plantographic examinations of 12 healthy children of the same age.Results. In patients with spondylolisthesis, the mean value of the anterior t and intermediate s plantographic bearing indices were significantly lower than those of healthy children. At the same time, in tests with an increased load on the foot in patients, there was no significant increase in the mean anterior t and medial m indices, which indicates the dynamic rigidity of the transverse and medial longitudinal arches. The value of the lateral plantographic index l showed its significant pathological increase compared with the normal value at double-bearing load, which indicates the static rigidity of the lateral longitudinal arch. Correlation analysis demonstrated that, against the normal state, the bearing ability of the feet in sick children is realized through a pathological strengthening of the functional relationship between the arches of the foot at double-bearing load and a non-physiological reduction of the interaction between arches at single-bearing load.Conclusion. In children with severe forms of vertebra spondylolisthesis, the parameters of plantographic characteristics indicate the rigidity of the arches of the feet and the distortion of their bearing pattern. It is necessary to take into account the aggravating effect of rigid feet on the state of the spine and include the examination of the bearing function of the feet in the algorithm for the comprehensive diagnosis of children with spondylolisthesis.