The mechanical properties and phase morphology of blends of nylon-6 with various acrylonitrile-butadienestyrene (ABS) materials and compatibilizers are explored. The main focus was on nylon-6/ABS blends compatibilized with one particular imidized acrylic polymer that is miscible with the styrene-acrylonitrile (SAN) matrix of the ABS and has nearly optimal content of functional groups (anhydride and free acid) for reaction with nylon-6 to form graft copolymers in situ at the polymer-polymer interfaces. The effects of compatibilizer content, rubber concentration and the mixing protocol on the mechanical properties of these blends were extensively explored. In general, the most efficiently dispersed ABS domains in the nylon matrix led to the lowest ductile-brittle transition temperatures and the maximum tensile modulus for the super-tough nylon-6/ABS blends. The effects of varying the functionality and miscibility characteristics of imidized acrylic polymers on the mechanical properties and morphology of nylon-6/ABS blends were also investigated. Some other types of polymers with a high anhydride content were also tested as compatibilizers for this system. It appears that compatibilizers with high levels of reactive functinality are not very effective; hence, there is an optimal level of functionality.