Abstract : Acute lymphoblastic leukemia (ALL) is the most common cancer in children and adolescents. Chemotherapy for leukemia has many side effects, toxicity, and length of stay that will affect the patient's quality of life. One of the factors that contribute to children's quality of life, including in the case of leukemia, is sleep disorder. The aim of this study is to analyze the risk factors that cause sleep disorder in ALL. This study is an analytic study with a cross-sectional design conducted in children with a diagnosis of acute lymphoblastic leukemia at Haji Adam Malik General Hospital Medan who met the inclusion and exclusion criteria from October 2021 to April 2022. Subject's parents were interviewed based on the questions on the CSHQ questionnaire. Out of 50 children with acute lymphoblastic leukemia, 33.3% of male and 45% of female in this study had sleep disorders. Based on nutritional status, 63.2% of children with normal nutritional status and 22.6% of malnourished children experienced sleep disorders. Based on the type of medication, 50% of children given prednisone therapy experienced sleep disorders. Prednisone is the most chemotherapy treatment agent and it has sleep disorder effect in ALL patients, there is a significant partial association between nutritional status and sleep disorders in children with ALL, there is a significant association between the type of medication and sleep disorders in children with ALL.