Introduction: Leukemia, particularly acute lymphoblastic leukemia (ALL), is the most common cancer among children and adolescents in Brazil, significantly impacting the Unified Health System (SUS). This study aims to analyze the epidemiological profile of hospitalizations for leukemia in the SUS from 2021 to 2024, considering age, sex, and hospitalization characteristics, to support improvements in care strategies and public policies for pediatric cancer in Brazil. Methods: This cross-sectional study used data from the DATASUS platform. The variables analyzed included the total number of hospitalizations for neoplasms and leukemia in Brazil, segmented by age group (0-19 years) and sex, from 2021 to 2024. Results: From 2021 to 2024, hospitalizations for neoplasms among children and adolescents in Brazil increased. In 2021, there were 60,280 admissions, with 35.08% due to leukemia, predominantly among males (12,424 cases), and in the age group of 1-4 years (6,657 admissions). In 2022, admissions rose to 61,865, with 34.59% of these for leukemia, maintaining the same sex and age patterns. In 2023, there were 64,684 admissions, of which 33.37% were for leukemia, with males (12,560 cases) and the 5-9 age group predominating. In 2024, until November, 62,814 admissions were recorded, 34.02% for leukemia, again with males and the 1-4 age group prevailing. Conclusions: The persistently high rate of leukemia-related hospitalizations among children and adolescents in Brazil, predominantly in males and in the 1-4 age group, emphasizes the need for strengthened early diagnosis and treatment efforts in the SUS. The increasing hospitalization trend from 2021 to 2024 highlights the urgency of improving public policies and the importance of an integrated approach to pediatric cancer care in Brazil.