Different crude extracts of some endemic Hypericum species (H. thymbrifolium, H. spectabile, H. pseudolaeve, H. neurocalycinum, H. malatyanum) and H. perforatum were analyzed using a microdilution assay for antimicrobial activity against several microorganisms. It is observed that all extracts showed activity against tested Gram positive bacteria (Staphylococcus aureus, Meticillin resistant S. aureus and Streptococcus epidermidis). The most active extracts were from H. neurocalycinum and H. malatyanum which showed potent activity with lowest MIC (4.8 mu g/mL) value against more tested Gram positive bacteria. Additionally, it was also found that some extracts of H. spectabile and H. pseudolaeve had antifungal activities against C. albicans. These endemic species were evaluated for antimicrobial activity for the first time in the literature.