The Tatra Shepherd Dog is one of five Polish native breeds of dogs originating from the Polish Tatra Mountains. The objective of the study was to determine genetic variation in a population of 60 dogs of this breed, based on polymorphism of 18 microsatellite (STR) markers, recommended by ISAG for canine parentage testing. The analysis showed considerable genetic variability in the studied loci. The 100 alleles identified in the test material were used to determine the polymorphism of the discussed markers. The highest polymorphism was found in the locus AHT171, in which 8 alleles were identified and PIC and H O values exceeded 0.8. The lowest polymorphism was detected for AHTk211, in which 3 alleles were determined, and PIC and H O values were 0.233 and 0.281, respectively. Average F IS had a low negative value, which suggests zero inbreeding of the studied breed. The probability of parentage exclusion estimated for the 18 markers totalled 99.996%.