The present invention relates to new aqueous microemulsions containing one or more organic insecticide compounds and to their use for plant protection, including seed and crop protection, and protection of non-living material. The formulation according to the invention comprises: a) at least one organic insecticide compound I having a water solubility of not more than 5 g/l at 298 K and 1013 mbar； b) at least one polar organic solvent selected from ketones, esters, amides and ethers, each having from 6 to 8 carbon atoms； c) at least one alcohol having from 6 to 8 carbon atoms； d) at least one surfactant selected from anionic surfactants and non-ionic surfactants； e) at least one non-polar organic solvent different from b)； and f) water.
