The role of the nurse in the pediatric department is very important and extensive. Health care carried out by a nurse includes observation, monitoring, assessment and finding subjective and objective factors that negatively affect the child's health condition. Her role includes prevention of infection, bleeding, hospitalism in children and health education of children and their parents. The nurse plays a very important role in the preparation and application of medicines, such as the preparation of medicine in a digester and in the implementation of various medical procedures such as lumbar puncture, bone marrow puncture, lymph node biopsy and bone marrow transplantation. It is important that the nurse has the necessary knowledge and skills in order to plan and implement the health care of a child with leukemia in cooperation with other members of the health care team. In addition to the above, she is responsible for the order and cleanliness of the department, organizing and controlling the work of the support staff. Nurses have greatly contributed to the success of modern medicine thanks to their expertise in the process of caring for children with leukemia. Understanding the classification of leukemia and the terminology associated with diagnosis and treatment provides a framework for nurses to provide the specialized care needed by children with leukemia. Nurses are often the first to come into contact with children, therefore they play a major role in recognizing the first signs and symptoms of illness, and the importance of their role continues throughout the entire treatment process.