Recent mechanistic insight into the synthesis of metal nanostructures by attachment-based growth is highlighted in this review. From quasi-spherical particles to nanowires, nanodendrites, and heterostructures built from nanoparticles as primary building blocks, the principles of oriented and misoriented attachment of metal nanoparticles are discussed within the context of diverse synthetic conditions. From this survey, a greater understanding of this growth mechanism emerges to provide general, and potentially greener, principles for the synthesis of advanced metal nanostructures, including those with applications in catalysis. Fig. 5 TEM images of (a) spherical Pd nanocrystals obtained by heating Pd(acac) 2 in TOP and oleylamine, (b) Pd nanodendrites prepared by heating Pd(hfac) 2 in oleylamine, and (c) Pd bundles formed by heating Pd(acac) 2 in oleylamine. (Adapted with permission from ref. 50.