It has been realized that nanotechnology has significant impact in all felids of science and hence, it has generated impressive applications in almost every area of work. However, one can foresee some major disadvantages that cannot be neglected. In this paper we have given a brief introduction to nano materials and then look into the potential dark side of Nanotechnology and Nanoparticles. Since thousands of publications on the use of nanotechnology are appearing every year; it is pertinent that we should look at its negative or darker side also. In this review, negative impact of Nanotechnology in the realm of health, agriculture and environmental concerns has been looked into. This review also emphasizes the need for strict policies regarding the research as well as nanoproducts. It is not only the end product but the protocols for synthesis of nanomaterials and nanomaterials have been found to have negative impacts. Impacts may be due to the side products, due to the size of the nanoparticles, due to waste or even due to their novel properties. Hence a brief introduction to Nanotechnology and its unique properties is also touched upon
