Taxa of Mentha L. were evaluated during 2011-2014. Thirty-five taxa were evaluated in terms of morphological parameters, in term of constituents (quantity and quality of essential oil, content of phenols and flavonoids) and insecticidal activity of essential oils on Musca domestica and Culex quinquefasciatus Say. Essential oils were obtained by steam-distillation and their composition was determined by GC/MS. Content of phenolics was evaluated by Folin-Ciocalteu assay, content of flavonoids was determined by aluminium chloride colorimetric assay and antioxidant capacity was determined by DPPH method. Insecticidal activities were evaluated according to the modified WHO methodology. The best insecticidal activity, for Musca and Culex, was observed in case of essential oil with majority stake of piperitenone oxide, namely essential oils obtained form taxa M. suaveolens 'Variegata' and M. sp. 'Cinderella'.