Leukemia is white blood cells cancer, which characterized with production of immature blood cells. Overcrowding of bone marrow with this abnormal immature cells, which interference with normal blood cells production, this may be lead to hyperleukocytosis, cytopenias, liver and kidney failure. In this study reports a case series of four patients with acute leukemia were studied. From this study, we concluded that hyperleukocytosis and cytopenias, disturbance in liver and kidney function were correlated with ALL than in AML.