The article is dedicated to skeletal adaptation and compensatory mechanisms developed by children with unequal leg length. The study was bases upon analysis of 344 pelvic X-rays obtained in children of various age, and examination of 125 volunteers, in whom unequal leg length was modeled. The results show that the most objective method of evaluation of pelvic and spinal deformation in children with unequal leg length is the system called "the topography of optical spine deformation", which allows determination of the optimal volume of compensation. According to the study, unequal leg length causes the most prominent pelvic asymmetry and spinal deformation in early childhood due to certain anthropometric peculiarities (lesser distance between the femoral heads in small children.) Thus, early diagnostics and adequate timely correction of unequal leg length are necessary.