Acute leukemia which is the most common cancer in children is a heterogeneous group of clonal malignancies. The conversion of the leukemic cell lineage during the course of the disease or later is termed lineage switch. It has been rarely reported in the literature. In leukemia lineage switch, conversions from lymphoblastic leukemia to myeloid leukemia or vice versa are reported. Herein, we report a 7-year-old child with acute lymphoblastic leukemia which switched to acute myeloid leukemia upon relapse.