We report a new variety of acetabular fracture. This posterosuperior fracture affected the acetabular roof and the iliac wing as other superior fractures and presented a supplementary fracture line disjoining the major part of the posterior wall. Two our knowledge, in a series of 940 fractures of the acetabulum, Letournel alone described two cases of superior fractures involving the roof with a slightly anterior fracture line in the iliac wing but with an intact posterior wall in both cases. The patient was treated by osteosynthesis via the iliofemoral approach described by Judet-Letournel. This approach was warranted to achieve simultaneous exposure of both columns and the posterior wall which was separated from the proximal fragment by a secondary fracture line. At six months, the functional result was considered good as assessed by the Postel-Merle-d'Aubigné score. This case widens the Letournel classification and emphasizes the importance of computed tomography to evaluate, in superior fractures of the acetabulum, the volume of the posterior wall fragment and its continuity with the cranial portion of the acetabulum and the iliac wing. For fixation, the surgical approach must be chosen individually according to the position of the fracture lines visualized on the preoperative computed tomography.