Human exposure to nanoparticles has increased considerably due to anthropogenic activities dominated by coal and diesel oil fuel combustion. Not only the inhalation of nanoparticles, which nowadays is considered to be the most significant via of exposure to nanomaterials, but also the gradually more employment of nanoparticles in products such as cosmetics, deodorants, textiles, or even food is broadening the exposure to those materials. Developing the previous applications will obviously require the use of analytical methodologies to analyse biological matrices in order to assess potential risks in their use and take appropriate corrective actions. This chapter describes a general overview of the most important analytical techniques for the analysis of nanoparticles in biological matrices.