This study deals with illegal employment of third-country nationals in Austria. Illegal employment is defined as an economic activity carried out in violation of provisions set forth in legislation, specifically the Act Governing the Employment of Foreigners. In particular, the study takes a look at the following aspects of illegal employment: (i) prevention measures, (ii) identification of illegal employment, (iii) sanctions for employers, and (iv) consequences for third-country nationals found to be working illegally. The study also presents available statistical data and highlights challenges and good practices.