Summary Limping as the most frequent sign causing treatment decisions in patients with leg-length discrepancy, has become possible to measure using gait analysis. Consequently, observation of its changes may be a valuable guide in limb-lengthening treatment using Ilizarov technique. In this paper, we present results of repeated laboratory gait analysis in 23 patient with limb-length discrepancy treated with use of Ilizarov external fixation technique. We analyzed time, dimensional and kinetic gait parameters. The evaluation of vertical ground reaction force elements values was conducted twice--during standing (static phase) and walking (dynamic phase). Each examination was performed before treatment, during distraction, consolidation and after frame removal. Observed values of chosen gait parameters revealed substantial changes during initial treatment period comparing to those before treatment. In the course of time they normalized. Kinetic examinations proved also the initial reduction of ground reaction forces. Relations between vertical pressure forces were also disturbed in both static and dynamic gait phases. This determines the future course of search for optimal treatment solutions in patients treated by distraction with Ilizarov frame. Observed change regularities allow to control the course of treatment and determine indications for further distraction.