The purpose of this publication is to provide information on basic legal regulations that must be applied when employing or hosting foreign scientists or academics in the environment of Czech public universities or public research institutions of the Academy of Sciences. During the international mobility of researchers, Czech, European and international law in the field of visas, access to the domestic labor market and compliance with the rules of Czech labor law, public health insurance and social security must be taken into account. The principles of international income taxation, especially from dependent activities, cannot be neglected either. International mobility is usually financed from public sources or through foundations, whether Czech or foreign providers, so it is also necessary to comply with the rules of the financial support provider, which may be difficult in some cases. The issue of international researcher ́s mobility is therefore overly complex.