The invention relates to a method for protecting plywood comprising a number of veneers against the detrimental effect of micro-organisms, wherein the method comprises: a) providing a number of veneers, wherein each of the veneers has two sides and a thickness of 0.5 - 4.0 mm b) treating the number of veneers by applying an aqueous composition comprising biocide, especially propiconazole, on at least one side of each of the veneers, wherein the amount and concentration of the aqueous composition comprising biocide, applied on the veneer, is chosen such that the average moisture content of the treated veneer is at most 10 weight-% when the target retention level for the biocide is 500 - 2000 g/m3 and c) gluing together the treated veneers with a binder composition to produce plywood. The invention further relates to plywood and to the use thereof as well as to the use of an aqueous composition comprising biocide.
