Phytoremediation of metals is being developed as a cost-effective and environmentally friendly solution for heavy-metal–contaminated sites. In recent years, major scientific strides have been taken in understanding the soil chemical and plant molecular-genetic mechanisms that drive metal hyperaccumulation in plants. Because hyperaccumulators are mostly low biomass and slow-growing plants, current research is focused mainly on designing transgenic plants that can overcome this deficiency. Added to the complexity of plant-metal interactions are influences of the environment, specific matrix factors that controls the chemical speciation of the metal, and interactions of other toxicants that may be present at the site. Extensive progress has been made in characterizing and modifying the soil chemistry of the contaminated sites to promote/accelerate metal phytoremediation. However, extensive field deployment of this technique on a large scale is still being hampered by a lack of specific understanding of the complex interactions between metal, soil, and plant systems that are instrumental in metal uptake, translocation, and storage in plants. A multidisciplinary research effort that integrates the work of plant biologists, soil chemists, microbiologists, and environmental engineers is essential for the success of phytoremediation as a viable soil cleanup technique in metal-contaminated sites.