The aim of this study was to evaluate the long-term results of conservative and surgical fragment excision treatment in patients with Pipkin type 1 fractures of the femoral head associated with posterior dislocation of the hip by a randomised controlled trial. Sixteen patients were randomly divided into two groups: the conservative group was treated by closed reduction, and the surgical group was treated by closed reduction followed with fragment excision. Functional outcome was determined using the Thompson and Epstein score and the Merle d'Aubigne and Postel score. Outcome of the conservative group was worse than that of the surgical group (p = 0.032). The randomised controlled trial proves surgical fragment excision after closed reduction is an effective treatment for Pipkin type 1 fractures.