A facile method for the synthesis of Au-based hybrid nanocrystals is described by employing pre-synthesized nanocrystals as seeds for heterogeneous nucleation and growth of Au. The seeds are CdSe, PbSe, FePt, Cu2O, or FePt-CdS nanocrystals. The sites of heterogeneous nucleation can be accurately controlled for nanocrystal seeds with a nonspherical shape.