A process for impregnating wood and wood products wherein the wood is treated with a composition comprising;(A) a salt of an organic or inorganic acid and an organopolysiloxane which contains SiC-bonded radicals with basic nitrogen in amounts of at least 0.5% by weight of basic nitrogen, based on the weight of this organopolysiloxane,(B) a water-repellent active compound which is not solid at 20.degree. C. under 1020 hPa, with the proviso that the water-repellent active compound can also be an organosilicon compound which is solid at 20.degree. C. under 1020 hPa and dissolves under these conditions to the extent of more than 50 parts by weight in 100 parts by weight of (A), if appropriate mixed with an organosilicon compound containing basic nitrogen in amounts of 0% to 0.5% by weight, based on the weight of this organosilicon compound, and/or silicic acid esters, and(c) water.Wood and wood products treated with the composition described above exhibit substantially reduced water absorption.