Teucrium persicum Boiss. is an Iranian endemic plant which belongs to the Lamiaceae family and has been used to relieve pains in traditional Iranian medicine. We have previously found that treatment of prostate cancer PC3 cells with Teucrium persicum extract leads to the formation of small populations of epithelial cells. β-Catenin is a component of cell adherens junctions in epithelial cells and therefore, in this study, we have investigated the effect of Teucrium persicum extract on expression, cellular localization, and transcriptional activity of β-Catenin protein in PC-3 cells. Indirect immunofluorescence microscopy results showed that the cells treated with T. persicum extract had higher levels of β-Catenin protein at the cell membrane. Western blotting experiments produced consistent results. Gene expression studies by using a few β-Catenin-target genes including c-MYC, CYCLIN D1, and a reporter Luciferase gene under the control of several β-Catenin/TCF binding elements showed that treatment of PC3 cells with the methanolic extract of T. persicum decreases the transcriptional activities of β-Catenin. The results of this study provide further support for the anticancer properties of T. persicum. Definitely, more detailed molecular investigations are needed to find the mechanism(s) behind these effects. Highlightsβ-Catenin protein is a main component of Wnt signaling pathway and adherens junction.Activation of Wnt signaling pathway affects translocation of β-Catenin.Teucrium persicum extract induces β-Catenin localization at cell membrane.Teucrium persicum affects the transcriptional activity of β-Catenin.It stabilizes E-cadherin/β-Catenin protein complex and adherens junction.