Leukemia is a malignancy affecting the blood-forming tissues, including the bone marrow, and represents the most frequently diagnosed cancer in the pediatric population, accounting for over one-quarter of childhood cancer cases. The disease disrupts normal white blood cell production, leading to immune suppression and increased vulnerability to infections. Impaired immunity frequently necessitates intensive management of both opportunistic infections and the malignancy itself. This review examines the complete clinical spectrum of pediatric leukemia, encompassing diagnostic methods, disease progression, physiological alterations, and therapeutic strategies. Advances over recent decades, supported by large-scale clinical trials and cohort analyses, have introduced novel treatment agents that improve survival outcomes while reducing treatment-related complications. Overall, the review highlights contemporary best practices in managing childhood leukemia.