Introduction. Multiplane axial deformities, leg length discrepancy and body disproportion are most common deformities in skeletal dysplasias patients. All of these pathologies are good indication for external Þ xation treatment with use both monolateral and circular frames. Aim of the study is to analyze results of bone deformities treatment with external fixation in patients with bone dysplasias.Material and methods. Material consists of 25 patients with different types of bone dysplasias (Ollier disease - 10, Blount disease - 7, vitamin-D resistant rickets - 2, Elis van Creveld syndrome - 2 and other - 4). Total number of 45 bone segments were treated (30 tibias, 15 femurs). Age at the beginning of treatment ranged from 7 to 20 years (mean 13,5). The main indication for treatment was axial deformity in 39 segments and LLD in 31. Mean value of deformity was 18° ranged from 8 to 43. In 6 patients short stature was additional indication for surgical treatment. Follow up ranged from 6 months to 10 years (mean 4 years, 8 months). All patients were divided into two groups according to etiology: 1. - Ollier disease, 2. other bone dysplasias.Results. Complete axial correction was achieved in all treated segments. In segments with shortening mean 5,4cm lengthening was achieved (ranged from 3 to 9). Lengthening index ranged from 1,0 to 2,2 cm/month (mean 1,43) and was statistically different in groups: 1. - 1,28 and 2. - 1,68 month/cm.Conclusions. Ilizarov distraction method is save and effective treatment of deformity correction in bone dysplasias with low rate of complications. It allows simultaneous multilevel corrections. In Ollier patients healing index is lower than in other types of bone dysplasias.