Devices and applications that exploit nanoparticle (NP) coupling interactions require the controlled arrangement of primary NPs into defined supracolloidal assemblies. Solution self-assembly of polymer-coated NPs is a scalable approach; however, imparting assembly directionality is still challenging. Current strategies for achieving such directionality include surface encoding of distinct NP sites with polymer ligands, which adds significantly to the complexity of the approach. Moreover, at present, a mechanistic understanding of the self-assembly behavior of polymer-coated NPs is limited due to the hurdle of locally resolved, quantitative characterization under the assembly condition. Herein, we reveal that polystyrene-coated gold nanorods can undergo directional tip-to-tip self-assembly, even when they are uniformly coated with a polymer ligand layer. Our results suggest that directionality in the self-assembly arises from the intrinsic surface charge of the nanorods. These findings open up a straightforward and generic way for achieving directional assembly of anisotropic NPs for future materials concepts.