Environmental hazards have motivated the development of a novel perspective of urban environmental quality as a planning strategy prerequisite for the integration of greenery resources in urban infrastructures. The accurate genotype stress response presents a condition for urban adaptation of plants. The goal of this review paper is to present phytoremediation at molecular levels via genes related to transport, accumulation and sequestration/detoxification of heavy metals from the environment. The overexpression/alteration of the native plant-specific gene(s) and transgenic plants whose metal-uptake proteins and metal-efflux proteins enable efficient metal uptake and transport, give rise to transgenic approaches. In a line with this, overexpression/alteration of a gene(s) encoding for phytochelatins and glutathione increase the sequestration of toxic HMs in the vacuoles. Since tolerance to high levels of metals by hyperaccumulators is under genetic control, many studies used genetic approaches to define the genetic determinants of these hyperaccumulators. Many plant species, particularly members of the Brassicaceae family are known heavy metal hyperaccumulators. This paper examines molecular aspects of hyperaccumulator plant species from genera Brassica, Noccea, Alyssum and Arabidopsis in phytoremediation of heavy metal polluted environments, and provides an overview of potential transferable genes that could improve metal tolerance and/or accumulation, as the major targets for phytoremediation. Therefore, plant species identified to have the potential to grow and remediate the heavy metal polluted urban environments require greater attention.