Abstract: The invention relates to a wood-impregnating agent, which is an emulsion, dispersion or solution of a cationic, quaternary, amphoteric and/or special non-ionic surfactant, the surfactant or surfactants being poorly soluble in water and the dispersion or emulsion having a mean particle size diameter or a mean droplet size diameter smaller than 1 .mu.m. Preferable surfactants include cationic and/or quaternary surfactants or compounds from the group of imidazolines, benzyls, alkyls, dialkyls, monoalkyl-trimethyl, dialkyl-dimethyl, methyl-dialkoxy-alkyl, dialkylmethylbenzyl, diamidoamine and/or cationic and/or quaternary surfactants or compounds from the group of complex diquaternary compounds and/or the group of compounds which assume a cationic character in acid medium and/or non-ionic compounds from the group of fatty amine oxides, amine ethoxylate, and/or adducts of an ethylene oxide, which can be protonated on an heteroatom and/or amphoteric compounds from the group of betaines and/or ampholytes.