Acute leukemia (AL), a rapidly progressing hematological malignancy originating from the bone marrow, is primarily subclassified into acute myelocytic leukemia (AML) and acute lymphoblastic leukemia (ALL). Obtaining bone marrow samples can be challenging due to a number of reasons, including dilution or inaccessibility. Therefore, the present study focused on identifying novel diagnostic biomarkers in the peripheral blood for AL subgroups. Circular RNAs (circRNAs) are non-coding RNA molecules associated with various diseases. In the present study, to validate the distinct circRNA expression patterns distinguishing AML from ALL in peripheral blood, reverse transcription-quantitative polymerase chain reaction was employed. The diagnostic accuracy of hsa_circ_0020093 and hsa_circ_0022152 was then assessed using receiver operating characteristic curve analysis, and hsa_circ_0020093 was selected for further exploration using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses. The findings revealed that the expression patterns of hsa_circ_0020093 and hsa_circ_0022152 clearly differentiated ALL from AML in peripheral blood. The potential target genes of hsa_circ_0020093 identified were associated with critical biological processes such as protein serine kinase activity and cadherin binding. Furthermore, these genes are involved in signaling pathways including MAPK and mTOR. We propose that hsa_circ_0020093 plays a crucial role in initiating and promoting ALL by modulating downstream target genes through either hsa-microRNA (miR)-153-3p or hsa-miR-194-5p. The results of the present study demonstrate that hsa_circ_0020093 and hsa_circ_0022152 hold significant promise as diagnostic biomarkers for subclassifying AL into ALL or AML in peripheral blood. This discovery lays the foundation for future research endeavors aimed at elucidating the role of circRNAs in the pathogenesis and treatment of AL.