Purpose: The aim of the study was to compare the results of MRI, x-ray and clinical examination of ankle sprain in childhood. Consequences for treatment regarding to the results of the MRI were of spezial interest. Materials and Methods: MRI, x-ray, and results of clinical examination of 50 children with supination trauma of the ankle were analysed prospectively. Changes in treatment were of special interest. Results: 12 of 13 fractures could be shown in MRI (specifity 96%), 9 fractures were seen in x-ray (specifity 69%). 25 ruptured ligaments were exclusively diagnosed in MRI. One avulsion was seen in x-ray. Fibulotalar and fibulocalcanear ligaments have been ruptured most often. Bone bruise is a diagnosis of MRI. Depending on the results of the MRI examination in 34% of the 50 children clinical symptoms overestimated and in 12% clinical symptoms underestimated the injuries. Diagnosis of joint effusion and bone bruise in MRI had no effect on the treatment. Conclusion: MRI is the most precise method in verification of fracture, ligament injury and epiphyseal plate lesion compared to x-ray and clinical examination. MRI is able to replace x-ray diagnostics in ankle trauma. But, at the moment exhaustive implementation of MRI in trauma diagnostics is feasible not yet.