Thesis deals with the challenges of social integration of immigrants in Sweden and Italy. Although in the literature the comprehensive term "migrants" is used for people who migrate to other countries for economic, political and other reasons, this paper highlights an important difference between migrants and immigrants. Statistical data on immigrants in the territory of the European Union, with an emphasis on Italy and Sweden, and theories of migration, the most prominent of which are the neoclassical theory, the theory of world systems and the new economics of migration, are also processed. The aim of the work is to comparatively analyze the challenges of social integration faced by immigrants in Sweden and Italy at the legal, political and socioeconomic level and to determine challenging areas as well as those in which immigrants have successfully integrated. The results show that immigrants face challenges of social integration in both countries at the political level, which includes the right of political participation and access to education, housing and labor market as parts of socioeconomic level. Greater success at social integration is visible at the legal level and access to health services as a part of socioeconomic level.