Surface plasmon polaritons (SPPs) in chains of plasmonic nanoparticles have attracted significant attention due to potential applications in spectroscopy, sensing, and subwavelength manipulation of electromagnetic energy. On aspect of such waveguides that received relatively little attention is directionality. Here we explore waveguides that are not invariant under the reflection of direction. We show that, although the dispersion relations in such waveguides are still symmetric as is required by the electromagnetic reciprocity, a localized excitation applied to a central part of the chain can selectively couple to the SPPs propagating in only one of the two possible directions.