Many plants contain a variety of bioactive components. Therefore, it is important to know the bioactive properties of plant materials in order to be a reference for later researchers. In this study, it was investigated the antioxidant, antimicrobial and anti-quorum sensing activities of Usnea filipendula and Viscum album’s methanol extracts. To determine the antioxidant properties of the extracts; total phenolic, flavonoid and condensed tannin contents and ferric reducing antioxidant power analyses were performed. The antibacterial potential of plant extracts was tested by agar well diffusion method against Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, Salmonella typhimurium, Klebsiella pneumoniae, Proteus mirabilis, Listeria monocytogenes, Candida parapsilosis and Candida albicans microorganisms. Anti-quorum sensing activity was investigated on Chromobacterium violaceum bacteria. The highest total phenolic and ferric reducing antioxidant power was determined in U. filipendula extract. This extract inhibited the growth of S. aureus, K. pneumonia and L. monocytogenes microorganisms. The highest flavonoid and condensed tannin was observed in V. album extract. This extract was also able to prevent the growth of K. pneumonia and L. monocytogenes. None of the extracts showed anti-quorum sensing activity.