The aim of this study was to develop a method to detect a point mutation in the ribosomal S12 protein (rpsL) gene in streptomycin-resistant strains of Xanthomonas oryzae pv. oryzicola and X. oryzae pv. oryzae. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was developed to detect a point mutation in codon 43 of the rpsL gene in X. oryzae pv. oryzicola and X. oryzae pv. oryzae.