Aim. The aim of this paper was to compare the results of treatment of developmental dysplasia of the hip (DDH) with two different devices. Methods. In 118 DDH, authors employed, in a blinded randomized study, Teuffel-Mignon (TF) and Coxa-Flex (CF) devices. In this study checked 51 hips type IIC; 43 type IID; 15 type IIIA; 9 type IIIB, by Graf classification. Results. Hips Graf's type C were recovered in median 60.09 days, with TM in 50, with CF in 63,45; hips type D in 100 days, with TM in 58,50, with CF in 89.00; hips type IIIA in 103.60 days, with TM in 122, with CF in 94.50; hips type IIIB in 108.66 days, with TM in 121, with CF in 102.50. Conclusion. The linear multiple regression model shows a statistically significant associations between outcome and pathological type (P value<0.001), age at diagnosis (P<0.001) and device (P<0.02). The statistical model shows that on average for each day of delay in the diagnosis is needed more than half a day for the patient to recover. The model confirmed that patients with more serious pathologies need more time to recover. Authors think that importance of the treatment of DDH isn't only the type of device employed, but a precise and correct sonographic diagnosis. Very important is starting the treatment as soon as possible, when the infant's bone of hip is more plastic and easy to treat. The authors' opinion is that employing a device instead of another isn't important, fundamental is the choice of the right device derived to a long time clinical experience.