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.