Abstract: The present invention relates to quaternized polyamidoamines which have at least one structural unit of the formula VII in which R1, R2, R4 are straight-chain or branched organic radicals optionally containing heteroatoms; R5 is hydrogen or alkyl, R7 is hydrogen or alkyl or two radicals R7 together form a radical having a meaning given for R4, b is an integer from 0 to 50, and c is an integer from 1 to 50. The invention also relates to the preparation of the quaternary polyamidoamines, to compositions which comprise these compounds, and to the use thereof for cosmetic and pharmaceutical purposes, and in the fields of crop protection and textile dyeing. The present invention also relates to the use of quaternized polyamidoamines of the ionene type as biostatic or biocide and thus also biocidal compositions based on quaternized polyamidoamines.