The effect of sparse long-chain branching, LCB, on the rheology and associated processing behavior of polymers is distinctly different from the effect of broadening the molecular weight distribution (MWB). A brief review of sparse LCB and its effect on rheology and processing performance is presented first. Then, we focus on the degree of film-width reduction or necking during film-casting for several metallocene-catalyzed high-density polyethylenes with varying degrees of sparse LCB. It is found that the addition of sparse LCB reduces the degree of necking to a greater extent than broadening the MWD. Analysis of the uniaxial extensional and dynamic shear rheology with the pom-pom constitutive model reveals that a distribution of branches along shorter relaxation time modes is important in reducing necking at higher drawdown ratios. The results presented here can be translated to other polymer systems to make them exhibit a desired processing performance.