Breakpoints of the 15;17 translocation in patients with acute promyelocytic leukemia (APL) have been identified within PML and retinoic acid receptor a (RARA) genes in chromosomes 15 and 17, respectively. A wide heterogeneity was observed in the breakpoints on the PML and RARA genes. Therefore, amplification of the breakpoints region by polymerase chain reaction (PCR) with DNA has been considered to be difficult. In the present study, a method was developed to detect the 15;17 translocation with genomic DNA. Of 13 patients with APL, four were detected to have the rearrangement of genomic DNA. At present, reverse transcriptase-polymerase chain reaction analysis is one of the methods available for diagnosis and detection of the residual leukemic cells in APL. In this study, PCR analysis using genomic DNA of APL cells is proved to be useful for identifying the breakpoints of the PML and the RARA genes. Furthermore, this method is applicable to patients for whom RNA samples of the leukemic cells are not available.