The essential oil of mint species are widely used in food, pharmaceutical and cosmetic industries, growing throughout the world. Therefore, it is very important to know the chemical characteristics of the oil for economic use and enhanced performance of the end products. This study was carried out to determine mineral content, essential oil composition, antimicrobial and antioxidant activities of essential oil of Mentha piperita (L.) and M. spicata (L.) (Lamiaceae). Chemical compositions of hydro-distilled essential oils obtained from mint species leaves were analyzed by gas chromatography-mass spectrometry (GC-MS). For antimicrobial activity, the disc diffusion tests were carried out on E. coli line ATCC25922, P. aeroginosa line ATCC27853, S. aureus line 25923, S. pyogenes line ATCC19615 and C. albicans line ATCC10231, and the antioxidant activity was performed by using DPPH radical-scavenging method. It was determined that essential oil of M. piperita and M. spicata contains menthol and carvone as major components, respectively. Treatment of 5 ȝl, 10 ȝl 15 ȝl and 20 ȝl of the oil exhibited strong antimicrobial activity against S. pyogenes, S. aureus and C. albicans and E. coli, except P. aeruginosa. The antioxidant activity of essential oil of mint species lowered DPPH activity compared to ascorbic acid. The results demonstrated that mint species essential oil has clearly good antimicrobial activity against test organisms and acceptable antioxidant activity.