________________________________________________________________________________ AbstractGenetic diversity within and among three ostrich populations was investigated to corroborate whether these populations can be classified genetically as three different breeds. The DNA of South African Black (SAB, n = 30), Zimbabwean Blue (ZB, n = 32) and Kenyan Redneck (KR, n = 17) birds was assessed for genetic differences using 19 microsatellite loci. The number of alleles, as well as observed and expected heterozygosity of alleles, was determined. Genetic differentiation was measured using the F-statistic (F ST ) and Nei's genetic distance. Significant differences were observed among the three breeds. The SAB and ZB (F ST = 0.10 and Nei = 0.49) were genetically more similar, whereas the genetic distance between the KR and ZB breeds was the greatest (F ST = 0.13 and Nei = 0.61). The SAB strain exhibited the greatest observed heterozygosity (H o = 0.72) within its population while the ZB and the KR exhibited lower levels of heterozygosity (H o = 0.68). Based on these results, it was suggested that crossbreeding between these breeds would lead to heterosis in commercial ostrich enterprises. ________________________________________________________________________________