The present invention relates to new aqueous microemulsions containing organic pesticide compounds of limited water-solubility and to their use for plant protection, including seed and crop protection, and protection or non-living material. The aqueous microemulsions comprise a) at least one pyrethroid compound P; b) at least one organic solvent, selected from compounds of the formula I R1—(O-Alk)m-O—C(O)R2 (I) wherein m is 1, 2 or 3, R1 is H, C1-C6-alkyl or C(O)R3, R2 is hydrogen or C1-C4-alkyl, which may be unsubstituted or substituted with OH, Alk is C2-C6-alkylene, and R3 is hydrogen or C1-C4-alkyl, which may be unsubstituted or substituted with OH; c) at least one surfactant; and d) water.