AbstractrnNoug (Guizotia abyssinica) is an Ethiopian indigenous oilseed crop cultivated primarily for rnits oil and various economic importances. Its production and productivity is very low due to rndifferent constraints. The crop has receiveda littleattention in implementing improvement rnprograms and until very recently remained as underutilized oilseed crop. Crop improvement rnrequires the availability and understanding of the genetic resource in terms of genetic rnvariation and population structure.However, estimationofgenetic diversity of Noug with a rnwider representation of Ethiopiaâ€™s Noug growing regions using reliable molecular markerrnsuch as, microsatellite markers are rare. Thus, this study was aimed to uncover the extent of rngenetic diversity and population structure of 161 Noug genotypes collected from Ethiopia rnusing 13 microsatellite markers. The analysis revealed a total of 158 alleles generated with a rnmean of 12.15 per locus. All the 13 microsatellite markers were polymorphic and highly rninformative with a mean polymorphic information content (PIC) value of 0.82. The genetic rndiversity indices across the 14 collection regionsindicated the presence of higher genetic rnvariability among genotypes; including the Shannonâ€™s information index (I) which ranged rnfrom 0.89 to 1.26 with a mean value of 1.57. Observed heterozygosity (Ho), expected rnheterozygosity or gene diversity (He), unbiased expected heterozygosity (uHe) was0.17, 0.74, rnand 0.79, respectively. Genotypes from Shewa, Wollo, Gojjam, Tigray and Benishangul Gumuz (B/G), shared the highest in both expected hetrozygosity or gene diversity and rnunbiased expected heterozygosity. Individuals in the populations had a fixation index (F) rnranging from 0.67 to 0.80, with a mean of 0.77. The percentage of polymorphic loci (%Pl) inrnall the populations showed the highest (100%) and lowest (94.33%) with a mean of rn99.19%.The pairwise Neiâ€™s genetic distance showed the highest between Eritrea and Balern(0.892) followed by Eritreaand Illubabor (0.875).AMOVA revealed that 96.06% of the total rngenetic variation was attributed to within populations while only 3.94% was attributed to rnamong populations, indicatingthat the highest variation was between genotypes rather than rnvariation due to geographic distances. The NJ or UPGMA cluster and PCOA poorly grouped rnthe genotypes based on their origin indicating high gene flow or seed exchange across rngeographic regions.Furthermore, the model-based population structureanalysis weakly rninferred the predefinedpopulations into K=2 withconsiderable genetic admixture among tested rnpopulations.In conclusion,the microsatellites used in the present study are highly informative rnand could be used in future marker assisted breeding. Genotypes from Shewa, Wollo, Gojjam, rnTigray and B/G are identified as hotspot areas for their high genetic diversity. They also rnshowed the highest number of private alleles in which special focus should be given in these rnareas to implement breeding and future improvement programs.rnKey words/Phrases; Cluster analysis, Gene flow, Heterozygosity, hotspots, SSR Markers