BACKGROUND/AIM: Acute lymphoblastic leukemia (ALL) is a common childhood cancer characterized by high levels of blasts in the bone marrow, and it is influenced by genetic and microenvironmental factors. Genetic variants of the enzyme arylamine N-acetyltransferases 1 (NAT1), regulated by microRNA (miRNA) and long noncoding RNA (lncRNA), have been associated with predisposition to ALL. This study analyzed the characteristics of exosomes from patients newly diagnosed with ALL, patients already under ALL treatment, and healthy controls. MATERIALS AND METHODS: Exosomes were isolated from the serum of patients with ALL (n=13) and healthy children (n=18). The size, zeta potential, immunophenotype, and expression of miR-1290, miR-26b, miR-126, and lncRNA-H19 from exosomes were determined using a ZetaSizer Nano ZS instrument, flow cytometry and reverse transcription polymerase chain reaction, respectively. RESULTS: Exosomes from patients with ALL were larger and exhibited lower complexity compared with those from controls, with reduced levels of CD81(+)CD63(+)CD9(+) exosomes, particularly in newly diagnosed cases. A decrease in CD19 expression and an increase in CD34 expression were observed in exosomes from patients with ALL compared with controls, while CD10 was present in both groups. Additionally, exosomes from patients with ALL, particularly those with the pro-B (B1) subtype, showed significantly increased expression of miR-1290 and lncRNA-H19 compared with controls. CONCLUSION: These findings suggest that exosomes not only reflect the pathophysiology of ALL but may also play a crucial role in its development and progression. Furthermore, exosomes and their non-coding RNA content emerge as potential biomarkers for ALL diagnosis and prognosis, opening avenues for future research to explore their functional role and therapeutic potential.