Double Calcaneal osteotomy is the gold standard surgery for treatment of flexible flatfoot in patients who have both forefoot abduction and heel valgus. MCO (Medializing calcaneal osteotomy) corrects the heel valgus while Evan's osteotomy corrects the forefoot abduction. Most of the cases are satisfied with the results. They returned back to their normal activities within 2 months. The procedure has little complications the most common is wound dehiscence. Our study was on 16 feet all of them were diagnosed as flexible flatfoot with mean age 18 years old. We used AOFAS for follow up. Heel valgus , Mearye`s angle , TNC angle and VAS score were used for assessment .Most of the patients were satisfied either from the improvement of the pain or the shape of the heel. There are a lot of operations used in treatment of FFF like arthroeresis ,calcaneal stop ,evan's osteotomy but DCO is superior to those as it corrects both heel valgus anf forefoot abduction at the same session.