Abstract: Aqueous heavy duty liquid laundry detergent compositions useful for laundering fabrics and providing cleaning and softening benefits. Such detergent compositions contain at least 5%, by weight of the composition, of a surfactant component; from about 0.1% to about 10% of a quaternary ammonium fabric-softening agent having the formula wherein R1 and R2 are individually selected from the group consisting of C1-C4 alkyl, C1-C4 hydroxy alkyl, benzyl, and —(C2H4O)xH where x has a value from about 2 to about 5; X is an anion; and (1) R3 and R4 are each a C8-C14 alkyl or (2) R3 is a C8-C22 alkyl and R4 is selected from the group consisting of C1-C10 alkyl, C1-C10 hydroxy alkyl, benzyl, and —(C2H4O)xH where x has a value from about 2 to about 5; and such compositions contain less than 10 ppm of trimethylamine and dimethylamine impurities.