Background: Skeletal morbidities are a common initial presentation and outcome in acute lymphoblastic leukemia(ALL). Vitamin D plays a vital role in the physiological regulation of calcium and phosphate transport and bone mineralization. Also high (25(OH)) level and high vitamin d intake at the time of diagnosis and initiation of anticancer treatment were associated with improved outcome. Methods: Twenty five ALL patients admitted to hematology and oncology unit, children hospital Zagazig University in one-year .vitamin D (25 (OH)) level was assessed in all patients at diagnosis. Patients were classified into deficient vitamin D (0-20)ng/ml , insufficient vitamin D (20-30)ng/ml and sufficient vitamin D (30-50)ng/ml. Statistical analysis was done to determine relation between different groups and ALL patients characteristics. Results: Vitamin D deficient in 24% of patients, vitamin D insufficient in 48% of patients, and vitamin D sufficient in 28% of patients. There was high statistical difference between different groups regarding bone pain and sex. Conclusions: A non-sufficient level in childhood all (deficiency and insufficiency) is common in childhood ALL and this is related to bone pain as initial clinical presentation. Vitamin D is related to presentation and prognosis of ALL in children.