Introduction. Some patients with chronic myeloid leukemia (CML) have cytogenetically variant forms of translocation that lead to the formation of the coalesced BCR-ABL gene. The adverse course and progression of the disease are often accompanied by the appearance of additional chromosomal abnormalities in the karyotype of the patient.Aim — to describe a clinical observation of CML that occurred with the simultaneous presence of a variant translocation and a unique additional rearrangement in the patient’s karyotype.Main findings. A conventional cytogenetic analysis performed in a patient with primary immune thrombocytopenia and subsequently developed chronic myeloid leukemia revealed a variant translocation t(X;9;22)(q28;q34;q11.2), as well as an additional chromosomal anomaly t(1;8)(q23;q24.1). The presented case of observation shows that a standard cytogenetic study is an important part of the examination of patients with hematological pathologies, since it allows identifying chromosomal changes that have diagnostic and prognostic signifi cance.