The use of mint species in traditional and conventional medicine is mostly due to the presence of two classes of secondary bimolecules: monoterpenoids in essential oils and different structural types of phenolic compounds. Essential oils are known to act as antimicrobial, antispasmodic, carminative, and antiviral agents. In addition, essential oils of several mint species have been recently qualified as natural antioxidants. However, since oil composition is highly variable, the pharmacological activity strongly depends on certain chemorace. On the contrary, composition of phenolic constituents is relatively stable within species. The most important phenolic compounds in Mentha species are flavonoids. Mints are characterized by the presence of specific lipophilic flavonoids. Phenolic compounds of mints are found to poses a wide range of pharmacological activity: antioxidant, antiulcer, cytoprotective, heptoprotective, cholagogue, chemopreventive, anti-inflammatory, antidiabetogenic etc. However, besides healing properties some mint species can exhibit an adverse effect on human health. Here we report on botany, chemistry and activity of Mentha species with special respect to their significance for the modern phytotherapy.