Limping is a very usual reason for consultation in pediatric orthopedics. Limping could be classified in two groups: a painful or antalgic gait is caracterized by a decreased stance phase on the affected side. The trunk shift gait or Trendelenburg gait is caused by a decreased strength of the hip abductor muscles or by hip joint instability. Other modifications of gait patterns could be caused by neurologic pathologies that should not be misdiagnosed. Excepted when very severe, limb-length discrepancy is not causing limping in children. Excepted traumatism, most of the etiologies are specifically pediatric. Some mandate an urgent diagnosis and treatment as osteoarticular infections, or bone tumors, because delay in treatment could leave severe after-effects. A precise physical examination should dictate the proper imaging and biologic studies. In children, the diagnosis of tendonitis should not be kept without radiographic examination. One should remember that some hip pathologies could present as knee pain. Some pathologies never occur before a given age (for instance no hip transient synovitis before age 3), when other diagnoses should be systematically sought after (slipped capital epiphysis in teenagers). In case of uncertain diagnosis, the patient must be referred to an orthopaedic surgeon.