Organopolysiloxanes having aminoalkyl groups are prepared by (i) reacting (A) linear, cyclic or branched organopolysiloxanes with (B) aminoalkylsilanes which have an SiC-bonded, basic nitrogen-containing hydrocarbon radical and 2 or 3 hydrolyzable groups, or the partial or complete hydrolysis products thereof, optionally in the presence of (C) basic catalysts and/or (D) chain-terminating reagents, and (ii) optionally, after the reaction (i) neutralizing the optionally used basic catalysts (c),with the proviso that compounds (A), (B) and, when used, (D) are reacted continuously in a reaction space whose ratio of length to diameter is equal to or greater than four.