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Understanding of genetic diversity is essential in breeding programs and plant genetic resources management. In this study, the genetic diversity of 77 individuals of Teucrium from different regions of Iran was investigated using 18 ISSR markers. A total number of 198 bands were detected by ISSR primers, of which 184 (92.9%) bands with an average of 10.2 bands per primer were polymorphic. The Percentage of Polymorphic bands (PPL) ranged from 80 (UBC834) to 100% (UBC811, 812, 818, 820, 825, 826, and UBC855). The average Polymorphic Information Content (PIC), Shannon’s Information index (I), and Number of effective alleles (Ne) were 0.39, 0.526, and 1.6, respectively. The Analysis of Molecular Variance (AMOVA) revealed the higher level of genetic variation within populations (77%) compared to among populations (23%). Cluster analysis separated the individuals into three major groups using WPGMA based on Nei’s genetic distance coefficients. In addition, a model-based Bayesian approach subdivided the individuals into three major subgroups. The results of this study revealed that estimation of population genetics parameters using ISSR markers can be applied for assessing the differences between Teucrium populations and management of the genetic resources.