Nanotechnology is one of the fastest growing industries of today. Nanomaterials have entered everyday life with majority of the population being unaware of it and the potential dangers. Part of the population that is particularly at risk is workers who are exposed to nanoparticles in much higher doses than the general population. The aim of this paper is to show what nanoparticles are, who is exposed and what possible effects on health they might have. What primarily distinguishes nanoparticles from other substances is that due to their small size they receive new and not always predictable properties. There are numerous types of nanoparticles with different properties and effects on health. Applications are found in almost every branch of industry and production, which is why a very large number of workers is exposed. To assess the impact on health, a number of methods have been developed in the form of in vitro and epidemiological studies and animal experiments. The most important ways nanoparticles enter our system is the oral intake, inhalation and through the skin. Some of the industries in which we can find occupational exposure to nanoparticles are construction, health care, chemical and electrical industries. Professions that are among the most researched the coalworkers, metalworkers and scientists who study the nanoparticles. Numerous studies have shown connection between exposure to nanoparticles with diseases such as COPD, pneumonitis, chronic bronchitis, lung cancer and cardiovascular diseases. Exposure of workers in the workplace and their protection are regulated by several laws at the national and European level. Protection measures that are used are personal protection (in the form of protective equipment) and technical protection by creating a safe working environment.