This report presents an experience of polymerase chain reaction (PCR) analysis of T-cell receptor g- and bgene (TCR g, TCR b), and immunoglobulin heavy chain (IgH) gene rearrangements in 9 cases of primary systemic anaplastic large cell lymphoma. We showed 2 clonal IgH, 2 TCR g, 1 TCR b rearrangements. The genotype was B/T-cell in 1, T-cell in 1, B-cell in 1 and null cell-type in 6 cases. We used reverse transcriptase PCR (RT-PCR) to detect t(2;5)(p23;q35) and t(1;2)(q25;p23) translocations. T(2;5) translocation was demonstrated in 2 cases, there was no t(1;2) translocation. In most cases the molecular genetic results were found to be in agreement with immunophenotypic data.