The present invention provides an antimicrobial composition comprising: (i) an antimicrobial component comprising a quaternary ammonium component (I) consisting of (a) a component consisting essentially of a single compound of formula (A) wherein R1 and R2 are each independently a straight chain, unsubstituted and uninterrupted Ce-12 alkyl group and X" is chloride, bromide, fluoride, iodide sulphonate, carbonate or bicarbonate and (b) a component consisting essentially of at least one benzalkonium compound having the formula (B) wherein m is from 8 to 18, and X" is chloride, bromide, fluoride, iodide, saccharinate or sulphonate, wherein the ratio by weight of (a) to (b) is from 10:1 to 1:10 and (II) an additional antimicrobial component that does not comprise a quaternary ammonium compound (ii) at least one siloxane selected from those having the formula (H3C)[SiO(CH3)2]nSi(CH3)3, and (H3C)[SiO(CH3)H]nSi(CH3)3 wherein n is an integer of from 1 to 10 (iii) a polar solvent (iv) at least one surfactant wherein in terms of parts per million (ppm) the amount of component (iv) is no more than 20 times the amount of component (i) and wherein component (I) is the only component of the composition that comprises a quaternary ammonium compound.Cette invention concerne une composition antimicrobienne comprenant : (i) un composant antimicrobien contenant un composé ammonium quaternaire (I) constitué (a) dun composant comportant essentiellement un composé unique de formule (A), R1 et R2 étant chacun indépendamment un groupe alkyle à chaîne linéaire non substitué et non interrompu en Ce-12, et X" étant un chlorure, un bromure, un fluorure, un iodure, un sulfonate, un carbonate ou un bicarbonate et (b) dun composant comportant essentiellement au moins un composé benzalkonium de formule (B), m étant compris entre 8 et 18, et X" étant un chlorure, un bromure, un fluorure, un iodure, un saccharinate ou un sulfonate, le rapport en poids de (a) sur (b) étant de 10:1 à 1:10 et (II) un
