Nanotechnology, including the field of nanomedicine, promises to revolutionise/improve the way in which we live our lives. This atomic, molecular and macromolecular technology will introduce nanoparticles into our environment and our daily routine. In response to this exciting technology, toxicologists have responded with the development of a specialised subcategory of toxicology, nanotoxicology. This chapter will introduce nanotechnology and nanoparticles and examine the origins of nanotoxicology, drawing on epidemiology and respirable particle toxicology studies. These studies provide the foundation of what we today use to understand the toxicology of engineered nanoparticles. The focus of the chapter will be on human and mammalian nanotoxicology and will summarise the current understanding of the mechanisms of nanoparticle toxicity while describing the methodologies utilised to further knowledge in the area. In the context of the book, this chapter will briefly examine the impact of nanotechnology and the development of nanomedicines in relation to the pancreas. Nanomedicine relies heavily on nano-specific toxicological concepts and findings to provide safe medical applications. Success in this area requires a collaborative approach involving physicians, material scientists and toxicologists.