Methanolic extracts of 16 plant species, used in herbal and traditional medicinal preparations, collected from the same geographic region (Golcuk-Seben/Bolu, Turkey) were evaluated for their relative total phenolic contents, total antioxidant activities and their mineral contents in both dried plant samples and methanolic extracts. These species included Hypericum perforatum L., Thymus sipyleus Boiss., Equisetum arvense L., Achillea millefolium L., Tanacetum parthenium L., Thymus leucostomus Hausskn. & Velen., Usnea longissima, Herniaria incana Boiss., Teucrium polium L., Stachys bithynica Boiss., Anthemis nobilis L., Sambucus ebulus L., Berberis vulgaris L., Malus communis Desf., Matricaria chamomilla L. and Scorzonera laciniata L. Spectrophotometric Folin-Ciocalteu and DPPH free radical scavenging activity methods were performed to detect the total phenolic contents and total antioxidant activities of the methanolic extracts, respectively. The results show that the fruits of Berberis vulgaris L., have the highest antioxidant activity and aerial parts of Tanacetum parthenium L. have the highest total phenolics (92.62%). Mineral contents were determined by inductively coupled - mass spectrometry (ICP-MS). All dried plant samples and methanolic extracts contained high amounts of Si, Cu, Fe and Ca. The highest levels of Si, Cu, Fe and Ca were found in Equisetum arvense L., Anthemis nobilis L., and Thymus sipyleus Boiss. dried plant samples, whereas Se was only detected in Usnea longissima. The highest levels of Si, Cu, Fe and Ca were found in the methanolic extracts of Usnea longissima, Anthemis nobilis L. and Thymus sipyleus Boiss. respectively.