Leukemia, a malignancy of white cell lineage of hematopoietic system, is not a rare condition. It is quite common in children as well as adults. Being a systemic disorder, it is fairly well manifested in oral cavity. Apart from the oral manifestations due to leukemia, the anti-neoplastic therapy also contributes to oral complications in such patients. In certain patients, oral manifestations are the first presenting symptoms of this deadly disease. Awareness of dental clinician in this respect is invariably required. Dentists need to be well acquainted with proper knowledge of these manifestations as well as their management. It is also necessary to be aware about the special management considerations in such patients. Moreover, dentists, as a part of multidisciplinary team for managing leukemia are responsible for proper counselling and oral hygiene maintenance during the course of disease & therapy. This booklet, is a comprehensive compilation focusing on oral effects of disease & therapy in children & adults as well as special dental treatment considerations in such patients. The booklet is expected to be useful especially to students and practicing dental clinicians.