Introduction. Acute lymphoblastic leukemia (ALL) in adults exhibits BCR-ABL1 gene expression in 25-40% of patients, unpredictable prognosis, and adverse socioeconomic impact in resistant cases. Aim. To provide a comparative description of treatment outcomes and prognosis in clinical cases with BCR-ABL1-positive and BCR-ABL1-negative ALL. Materials and methods. The study presents the analysis of three females of 31, 43 and 67 years old with ALL, treated at the Institute of Oncology of Moldova in 2012-2021. Diagnoses were confirmed by cytochemical examination of the bone marrow (BM), immunophenotyping and quantitative real-time PCR of the peripheral blood (PB). Results. A 43-year-old patient with a 3-year history of cured left breast cancer presented to the hematology department with moderate hepatosplenomegaly, leukocytosis 75000/μL, and elevated lactate dehydrogenase (LDH) value to 570 U/L in PB and 55% L3 blast cell in BM. The BCR-ABL1-p210 transcript was 44.65%. Patients with BCR-ABL1-ALL had slight hepatosplenomegaly, normal levels of LDH in PB. A 31-year-old patient had leukocytosis of 14000/μL and blast cell count in BM of 70%. A 67-year-old patient had leukopenia 1900/μL, lymphocytosis 69% in PB and 83.3% of blast cells in BM. The ALL-BFM regimen was administered as first-line therapy. Complete hematologic response (HR) was achieved in BCR-ABL1-ALL. The patient with BCR-ABL1+ ALL was transferred to AVAMP protocol in combination with imatinib, achieving an unstable partial HR. Conclusion. The results of treatment of patients with ALL allow us to consider more severe spleno- and hepatomegaly, high leukocytosis and lactate dehydrogenase level in PC, L3 type and a positive p210 transcript of the BCR-ABL1 gene, as unfavorable prognostic factors.