Using a unique combination of template-based synthesis methods involving anodization, electroplating, and selective oxidation, we have synthesized engineered metal–oxide–metal (MOM) heterojunction nanowires in the Au–SnO2–Au and Au–NiO–Au systems for possible use in nanoelectronics. The template-based synthesis method used here is generic, and it has the potential to provide control over the structure and characteristics of the resulting MOM nanowires. By virtue of their heterojunction structure, MOM nanowires have the potential to overcome some of the drawbacks associated with all-oxide nanowire building blocks, and they present a rare opportunity to measure directly fundamental functional properties of nanoscale oxides.