L Leukemias are malignant neoplastic disease of the white blood cell-forming tissues. In the United States, approximately 2.5% of all cancers are leukemia, and 3.5% of deaths from cancer can be attributed to this disease. In Indonesia, about 30-40% cases of cancer in children is leukemia. Leukemias are classified as either acute or chronic, depending on the presentation of the disease. According to its type, leukemias are divided into acute myelogenous leukemia (AML), chronic myelogenous leukemia (CML), acute lymphoblastic leukemia (ALL), and chronic lymphocytic leukemia (CLL). The common clinical signs, among others, are anemia, weakness, fatigue, pallor of skin, thrombocytopenia of mucous membrane with associated bleeding tendencies and leukopenias resulting in increased susceptibility to infection. Gingival enlargement is the most common sign in patients with leukemia, with the prevalence is more common in acute than chronic leukemia, was apparent in 36% of the individuals with acute forms of leukemia and in 10% of those with chronic forms. Clinical features of leukemic gingival enlargement include bluish-red gingival with a shiny surface, the consistency is moderately firm but there is a tendency towards friability and spontaneous bleeding. Gingival enlargement is most common in acute monocytic leukemia (67% of cases), followed by acute myelomonocytic leukemia (18.5%), and acute myelocytic leukemia (4%). Periodontal treatment in patients with leukemic requires consultation between physicians and dental specialists who treat the patients.