This chapter reviews the concepts, synthetic methods, and theoretical predictions underlying the chirality of metal colloids with a particular emphasis on the size range of 10–100 nanometers. It focuses on chiral nanostructures built up from achiral anisotropic metal particles. Many applications of nanoscale chirality can benefit from optical characterization; chiral nanostructured systems in particular are currently being investigated for their use as powerful probes upon interaction with chiral biomacromolecules. Since the field of plasmonics is currently undergoing fast development, the chapter intends to focus on the recent work with isotropic and anisotropic plasmonic nanoparticles, and mentions chiral metal nanoclusters, placing each system within the context of the corresponding origin of the observed chirality. Although in many examples the mechanisms behind optical activity in metal nanoparticles cannot be easily identified, their chiroptical activity may in principle be restricted to two distinct origins: nanoparticles with individual chirality, and collective interactions between 3D ordered nanocrystals.