Six highly variable microsatellite loci were used to investigate the genetic diversity and population structure of the Garra rufa in Kermanshah and Bushehr provinces, Iran. All of the 6 microsatellite loci screened in this study showed polymorphism. A total of 90 individual fish from 3 populations were genotyped and 60 alleles were observed in all loci. The number of alleles per locus ranged from 6 to14. The average allelic number of these polymorphic markers was 10. The averages of observed (Ho) and expected heterozygosity (He) was 0.529 and 0.826, respectively. The genetic distance values ranged between 0.235-0.570. The UPGMA dendrogram based on genetic distance resulted in three clusters: Gamasiab population alone was classified as one and the other two populations as the second cluster. This study revealed a fairly high level of genetic variation in the microsatellite loci within the three populations, and identified distinct population groups of Garra rufa. This study gains significance for the analysis of the populations’ genetic diversity as well as the management of this important fish resource.