This thesis investigates the inventive performance of immigrants in Sweden. The results show that it is influenced by immigrants’ age at migration, region of origin, educational level, match between education and occupation and migration policy. In general, first-generation immigrants are less likely to patent than native Swedes. The exception is the group working in the high-tech knowledgeintensive service (KIS) sector, where first-generation immigrants are more likely to patent than natives mainly because they are more highly educated; furthermore, their high and similar representation in high-skill occupations as natives enable them to have as high patenting rate as natives when other variables are held constant. In most sectors, however, the main barriers to firstgeneration immigrants’ probability of patenting are their over-representation in low-skill occupations and their lower education-occupation match compared with natives. When the analysis is limited to inventors, first-generation immigrant inventors perform as well as their native counterparts. Second-generation immigrants with a non-Nordic European background perform better than native Swedes, which appears to be because they are positively affected from having more highly educated parents than their native counterparts and the close geographic proximity of their non-native parents’ region of origin to Sweden. The liberalization of migration after the inception of the European Economic Area (EEA) in 1994 had a negative effect on educational profile of new EU-15 immigrants to Sweden in the short run when compared with new immigrants from ‘Other developed regions’, but there is no such effect in the long run and no systemic effect on the EU-15 immigrants’ probability of becoming an inventor.