Nanotechnology is being promoted as a new generation environmental remediation technology with immense potential to provide cost-effective solutions to many of the most challenging environmental cleanup problems. Silver,copper, gold, iron oxides, titanium oxides are some of the commonly used nanoparticles (NPs) that can be used in environmental remediation. Further, nanoparticles can be used as selective and sensitive sensors to monitor toxins, heavy metals and persistent organic contaminants (POPs) in soil, water and air environments. But there appears pitfalls in the horizon! Toxicity issues have raised important environmental concerns. Although we need to make a trade-off but scientist are hopeful about benefits of this new "magic bullets", which far exceed their put-down-able drawbacks.