Artificial nanomaterials are relatively new products of recent decades. Although they have been available not for long, they already play a prominent role in various consumer goods and their importance for the wealth of society is rapidly growing. A new area of technology, nanotechnology, has been developed to design and produce nanomaterials in a controlled manner using specific tools and techniques. This chapter provides a brief discussion of vital issues related to nanomaterials and nanotechnology. Key classes of nanomaterials are identified and discussed. In addition to the review of their characteristics, examples of their applications are provided. Another aspect of rapid development of nanomaterials and nanotechnology is their possible harmful effects to the environment and human population. By proper combination of experimental studies, computational approaches, and risk analysis, such effects should be evaluated and predicted before mass production of new materials. An interdisciplinary approach provides the basis for safe and efficient application of nanotechnology.