The field of nanotechnology promises a plethora of advantageous features for various consumer applications. These include lighter and more durable sporting equipment, antimicrobial textile and clothing, increased sensitivity and efficacy within a wide range of medical applications, or utilization in packaging or additives in the food sector. The manipulation of materials at the nanoscale is considered as a new industrial revolution. Many of the proposed advantageous aspects associated with nanotechnology incorporate a risk of exposure to hazardous nanoparticles. However, to date there is no clear indication as to how nano-sized materials may interact with biological systems either acutely, or over a longer period of time. In this chapter, a historical overview of nanomaterial (NM) toxicology is provided, followed by a selected concise summary of the current understanding of the field toward the human health impacts of NM exposure. Finally, following a summary of these aspects, an outlook section highlights the direction in which the field is headed, as well as important considerations for future research within this discipline of nanotoxicology.