Method for preparing poly(hydroxymethyl)-functional siloxanes of the general formula I (SiO 4/2) k (R 1 SiO 3/2) m (R 1 2 SiO 2/2) p (R 1 3 SiO 1/2) q (O 1/2 H) t [(O 1/2) 2+y SiR 2 1-y -CH 2 -OH] s Formula I, which comprises reacting cyclic compounds having at least one unit of the general formula II [SiR 2 (OR 3)-CH 2 -O] n Formula II with water, wherein optionally one or more further hydrolyzable compounds of the general formula III R 1 3-z SiY 1+z Formula III may be present, and wherein R 1 is a hydrogen atom or a cyclic or acyclic, linear or branched, aromatic or aliphatic or olefinic, saturated or unsaturated C 1 -C 20 hydrocarbon residue or C 1 -C 20 hydrocarbonoxy residue or C 4 -C 40 polyether residue, each optionally substituted with Q 1, optionally interrupted by one or more groups Q 2 or comprising one or more groups Q 2, R 2 is a hydroxyl residue or a cyclic or acyclic, linear or branched, aromatic or aliphatic or olefinic, saturated or unsaturated C 1 -C 20 hydrocarbon residue or C 1 -C 20 hydrocarbonoxy residue or C 4 -C 40 polyether residue or Si 1 -Si 20 siloxanoxy residue, each optionally substituted with Q 1, optionally interrupted by one or more groups Q 2 or comprising one or more groups Q 2, R 3 is hydrogen or a cyclic or acyclic, linear or branched, aromatic or aliphatic or olefinic, saturated or unsaturated C 1 -C 20 hydrocarbon residue or C 4 -C 40 polyether residue or Si 1 -Si 20 siloxanyl residue, each optionally substituted with Q 1, optionally interrupted by one or more groups Q 2 or comprising one or more groups Q 2, Q 1 is a heteroatom-containing monovalent residue, Q 2 is a heteroatom-containing divalent residue or a heteroatom-containing trivalent residue, Y is a hydrolyzable group attached to the silicon via a heteroatom, k, m, p, q and t are greater than or equal to zero, s and n are greater than zero, y is 0 or 1, and z is 0, 1, 2 or 3. R 1 is a hydrogen atom or a cyclic or acyclic, linear or branched, aromatic or aliphatic or olefinic, saturated or unsaturated C 1 -C 20 hydrocarbon residue or C 1 -C 20 hydrocarbonoxy residue or C 4 -C 40 polyether residue, each optionally substituted with Q 1, optionally interrupted by one or more groups Q 2 or comprising one or more groups Q 2, R 2 is a hydroxyl residue or a cyclic or acyclic, linear or branched, aromatic or aliphatic or olefinic, saturated or unsaturated C 1 -C 20 hydrocarbon residue or C 1 -C 20 hydrocarbonoxy residue or C 4 -C 40 polyether residue or Si 1 -Si 20 siloxanoxy residue, each optionally substituted with Q 1, optionally interrupted by one or more groups Q 2 or comprising one or more groups Q 2, R 3 is hydrogen or a cyclic or acyclic, linear or branched, aromatic or aliphatic or olefinic, saturated or unsaturated C 1 -C 20 hydrocarbon residue or C 4 -C 40 polyether residue or Si 1 -Si 20 siloxanyl residue, each optionally substituted with Q 1, optionally interrupted by one or more groups Q 2 or comprising one or more groups Q 2, Q 1 is a heteroatom-containing monovalent residue, Q 2 is a heteroatom-containing divalent residue or a heteroatom-containing trivalent residue, Y is a hydrolyzable group attached to the silicon via a heteroatom, k, m, p, q and t are greater than or equal to zero, s and n are greater than zero, y is 0 or 1, and z is 0, 1, 2 or 3.