Nanotechnology and nanomaterials have become the "in" topics among researchers in the last few decades. The reason for nanotechnology's attractiveness is in the new opportunities that the technology offers. The paper gives a short overview of the emergence of nanotechnology, its basic terminology with focus on the types of nanomaterials, their unique properties and possibilities of application. The benefits of this booming field are evident in many areas including information and communication technology, energy storage, environmental engineering, chemical industry, food industry, medicine, pharmaceutical industry and cosmetics. On the other hand, the unique properties of nanomaterials which make them so attractive are also the cause of major concerns because of their potential harmfulness to human health and the environment. Nanomaterials easily enter the environment during production processes or in waste disposal, and affect the human body through occupational exposure and use of different products. Probably the biggest concerns of toxicologists at this point are the potentially harmful impacts of nanomaterials which are still insufficiently understood.