In this study, the chemical composition of the methanol, hexane and ethyl acetate extracts of Prunella vulgaris L. were investigated by gas chromatography-mass spectrometry (GC-MS) method. 2-hydroxy-5-methylbenzaldehyde (15.70%), linolenic acid (45.50%) and icosane (16.24%) were found to be the most abundant in methanol, hexane and ethyl acetate extracts, respectively. Following the determination of chemical components of the Prunella vulgaris L. extracts, their anti-microbial activities against certain human pathogenic bacteria were tested and minimal inhibitory concentrations (MIC) were determined. While some extracts of Prunella vulgaris L. show anti-microbial activity well above the standards (penicillin and tetracycline), it was determined that in general all the extracts showed good anti-microbial activity against these pathogenic bacteria.