With the emergence of health related side effects of synthetic substances, the trend towards natural products has increased and has directed researchers to determine their pharmacological properties. At the same time, the resistance of the microorganisms to the antibiotics used in the treatment revealed that they should be controlled without allowing them to gain resistance. In this study, the total phenolic content, volatile composition and antioxidant, antimicrobial, anti-quorum sensing and antitumor activities of Prunella vulgaris, Sambucus nigra and Calendula officinalis extracts were determined. The antioxidant capacity of the extracts was determined by the Trolox Equivalent Antioxidant Capacity (TEAC) method, volatile component analyses were determined by GC-MS, and antimicrobial activity was determined by the disc diffusion method. Chromobacterium violaceum 026 and Agrobacterium tumefaciens A136 were used to determine the anti-quorum sensing activity. Additionally, the antitumor potential of the extracts was determined by the potato disc method. Prunella vulgaris was the plant with the highest antioxidant capacity, while the extract with the highest antimicrobial activity was determined to be Sambucus nigra against Staphylococcus aureus ATCC 25923. The results showed that all extracts have anti-quorum sensing properties. Prunella vulgaris was the plant with the highest anti-quorum sensing properties. There was a correlation between the extract concentration and tumor inhibition. The Prunella vulgaris extract was found to have the highest antitumor activity. As a result, it was determined that the plants used in the study have the potential to be used in alternative medicine treatment and can be utilized for the control of microorganisms.