Teucrium persicum Boiss. an Iranian endemic plant is used in Iranian traditional medicine. E-cadherin transmembrane protein participates in adherens junctions and is the main partner for β-catenin protein. The GCMS analysis was used to detect the chemical constituents of the methanolic extract. Its effects on the transcription of the E-cadherin encoding gene, cellular levels, and localization of E-cadherin protein in PC-3 cells were investigated. About 70 chemical constituents were identified. Indirect immunofluorescence microscopy and western blotting results revealed the restoration of E-cadherin protein at cell adhesion contact sites in cells treated with T. persicum extract. Gene expression studies revealed that the extract increased the transcription of the E-cadherin encoding gene in PC-3 cells. These results suggest that T. persicum extract may contain potent compounds that provide further support for the anticancer properties of T. persicum. Surely, detailed molecular investigations are needed to find the mechanism(s) behind these effects.