Complications of flexible nailing of pediatric femur fractures include angular and rotational malunions, leg-length discrepancy, and, in rare instances, infection. To our knowledge, the development of a sclerosing type of chronic osteomyelitis, which appears most similar to chronic sclerosing osteomyelitis of Garre', has not been reported as a complication of, or associated with, flexible nail fixation of a pediatric femur fracture.