Limping is defined as an abnormal pattern of ambulation in which the swing and the stance phases of gait are markedly asymmetric according to the age and gender of the child. Limping should be considered as a serious complaint, which accounts for an important portion of the applications to the pediatric emergency services. In such a condition, the important thing is to differentiate the life-threatening causes. Acute trauma and many musculoskeletal diseases caused by neurologic rheumatologic and infectious conditions can give rise to limping. Limping can also be the first symptom of hematologic and oncologic malignancies such as leukemia, Ewing sarcoma and osteosarcoma, which may result in serious mortality and morbidity if there is a delay in diagnosis. In this article, a child with limping who was diagnosed as acute lymphoblastic leukemia is reported. Anahtar Kelimeler : aksama, akut lösemi, çocuk.