Osteopetrosis is a rare, inherited disease characterized by defects in osteoclastic function that results in defective bone resorption. When fractures are encountered, fixation is extremely difficult. Osteopetrosis patients have an increased predisposition to infection. If infection develops after a fracture, treatment is more difficult. In this paper, treatment is presented of a 49-year old female to whom proximal femoral nailing was applied for fixation of an osteopetrotic proximal femur fracture; and when it was unsuccessful, revision was made with a locked anatomic plate, which subsequently led to development of infection.