Tensile impact strength of blends of high-density polyethylene (HDPE) and acrylonitrile-butadiene-rubber (NBR) has been studied with special reference to the effect of blend ratio and com-patibilizer concentration. Even though the tensile impact strength of the blend is inferior to that of virgin plastic, a substantial improvement was observed in the tensile impact strength values of the compatibilized systems. The compatibilizers, phenolic modified polyethylene (PhPE) and maleic anhydride modified polyethylene (MAPE), act by locating at the interface due to their propensity to phase separation. By the addition of compatibilizers the interfacial tension is reduced and better mixing between components becomes possible, which results in finer and uniform morphology. The compatibilizers also improve the interfacial adhesion. The improvement in tensile impact strength has been explained on the basis of the blend morphology, that is, size, shape, and distribution of the rubber phase in the plastic matrix; tensile properties; and interfacial adhesion between the phases.