Slipped capital femoral epiphysis always requires surgical treatment. The operative technique depends on the degree of dislocation and the type of the slip. The goal of treatment is to achieve physeal stability until the epiphyseal plate closes without harming the further femoral growth. In situ fixation is generally recommended for slipped capital femoral epiphyses of a mild degree. For this purpose the technique of dynamic screw fixation (DSF) is applicable using a long cannulated screw with a short thread.DSF is easy to handle, provides sufficient long-term fixation of the epiphysis, does not promote premature closure of the epiphysis, and engenders few complications. Therefore, this technique is also applicable for the prophylactic treatment of the contralateral unaffected hip, which we always perform. Moreover, DSF can be used following gentle reduction of acute epiphysiolysis, if the amount of eventual residual dislocation does not exceed 30 degrees. We report our results with dynamic screw fixation of 29 slipped capital femoral epiphyses of a mild degree, and the prophylactic dynamic screw fixation of 34 unaffected hips. The fixation technique achieved a reliable stabilization with no visible growth disturbance of the femoral neck in all cases.