INTRODUCTION: Acute lymphoblastic leukemia (ALL) is the cancer with the highest incidence in childhood and adolescence, and pharmacotherapy is the primary form of treatment. OBJECTIVE AND METHODS: A systematic review of the efficacy and safety of polyethylene glycol (PEG)-asparaginase in acute lymphoblastic leukemia therapy in children and adolescents was conducted to compare it with native Escherichia coli L-asparaginase. PubMed, Web of Science, Science Direct, Cochrane Library, Scopus, LILACS (Latin American and Caribbean Health Sciences Literature) and EMBASE databases were selected. The following outcomes were analyzed: complete remission of the disease, event-free survival, overall survival, anti-asparaginase antibody level, hypersensitivity reactions, asparaginase and asparagine serum levels, number of postdiagnosis events, and overall mortality. Five randomized controlled trials were included. Analysis of the quality of evidence and risk of bias was performed using the Cochrane recommendation tool and the GRADE system. RESULTS: The assessment results suggest that the level of certainty on the technology addressed is relatively weak from a methodological point of view. Evidence is insufficient to assess the effects on health outcomes because of the limited number and power of studies and important flaws in their design or conduct in classifying PEG-asparaginase as a superior drug or not, in the pharmacotherapy of ALL in children and adolescents. PEG-asparaginase can be used as a substitute for native E. coli L-asparaginase, demonstrating similar efficacy and safety. CONCLUSION: The study may help decision-makers in the public health system to offer a more in-depth judgment on the therapeutic alternatives used to treat this neoplasm in children and adolescents.