Nested reverse-transcriptase polymerase chain reaction (rt-PCR) was performed on 58 leukemia patients at BIRDEM Laboratory, as a pioneering work in Bangladesh. Thirty of them were examined for the presence of BCR-ABL being clinically and morphologically diagnosed as chronic myeloid leukemia (CML) and 28 for PML-RARα fusion transcripts being clinically and morphologically diagnosed as acute promyelocytic leukemia (APL/ AML M3). The cases were selected for targeted therapy with imatinib mesylate and all-Trans retinoic acid (ATRA) to treat CML and APL respectively.