The treatment of haematological malignancy is multimodal and involves chemotherapy, radiotherapy and/or bone marrow transplants. With the advancement in cancer therapy, there is an increase in the survival of many children with childhood haematological malignancy. In addition, the late effect of the oncology treatment to the orofacial and dental development becomes significant in terms of the potential clinical impact that may affect the quality of life of the survivor. The severity of the long-term effects is dependent on the age of the child at initiation of treatment and whether chemotherapy is combined with radiation or not. The dental treatment may become more complex if the patient requires advanced restorative dental care and the roots malformation may complicate orthodontic treatment. Therefore these patients may require a scheduled careful preventive programme, long-term follow up, with prophylactic treatment and intervention at appropriate time to minimize the consequences of the disease and the given therapy.