In this study, we designed two PCR primers to amplify the region containing rs6548238. The AvaI restriction enzyme was selected to detect the SNP polymorphism. Sequencing the resulting bands validated the RFLP method. In conclusion, RFLP method is simple, sensitive and cost effective for genotyping of the TMEM18 rs6548238 polymorphism; thus, this method is most convenient for SNP analysis in large-size samples from Vietnamese population.