One of the major problems in treatment of leukemias is multidrug resistance, which is already present at diagnosis or develops after chemotherapy. The gene expression levels of multidrug resistance resistance 1 (MDR1), breast cancer resistance protein (BCRP) and lung resistance-resistance protein (LRP) were evaluated in blood samples of 20 CLL and 24 CML patients using RT-PCR. MDR1, BCRP and LRP expression levels were detected in 65%, 20% and 45% of CLL patients, and in 54%, 37% and 25% of CML patients, respectively. 20% of CLL patients and 33% of CML patients expressed none of the genes. The other 20% of CLL patients expressed all the genes. 17% of CML patients expressed all of these genes, and two of them rapidly progressed to acute leukemia. MDR and LRP expressions seem to be frequent events in CLL and CML patients; however no conclusion can be drawn on their prognostic role and response to the treatment.