The distal tibial oblique osteotomy (DTOO) can be used for cases of varus ankle osteoarthritis with a range of ankle joint movement of at least 10&[deg] or more. In the DTOO for ankle osteoarthritis, the contact area of the ankle joint increases and decreases the load pressure per unit area. Furthermore, as the width of the ankle mortice is restored through the realignment of the body of the talus, instability at the ankle joint decreases. In the original method, the external fixator was used, but we performed the DTOO by using a locking plate and achieved a satisfactory outcome. The important steps are protecting soft tissue, vein, nerve, and periosteum; resecting osteophytes to achieve good alignment; and grafting autologous bone mingled osteophytes. We introduce our surgical technique.