Bifunctional heterostructures composed of gold nanorods and hematite nanoparticle aggregates are prepared facilely through decomposition of ferric acetylacetonate on the surface Of the nanorods. The gold nanorod in the heterostructure is partially coated with the hematite nanoparticle aggregates. The hematite coating is porous. These heterostructures exhibit both plasmonic and superparamagnetic properties. They are well-dispersed in aqueous solutions. Such heterostructures will be potentially useful for many biotechnological applications.