Migration is topical in many counties, and attitudes towards immigration and ethnic diversity are volatile. In our longitudinal "Diversity Barometer ", we have studied changes in Swedes' attitudes towards immigration and ethnic diversity in Sweden since 2005, using a postal questionnaire sent to a random sample of the Swedish population aged 18-75. In this article, we analyzed data from 2020 (n = 1035) in comparison with previous Diversity Barometer surveys from 2005 to 2018. The findings showed that Swedes had increased contact with immigrants from the Middle East, Asia and Africa. The majority had good experiences of studying or working with people with foreign background, although those with bad experiences had also increased. Attitudes towards immigration and ethnic diversity were more positive in 2020, thereby stopping a negative trend that started with the refugee influx in 2015. Positive attitudes were more established among women, younger people, those with higher education, people living in larger cities and those with more contact with people with foreign background. Sympathizers of political parties closer to the left wing were more positive towards immigration and ethnic diversity. We used political correctness, contact theory, strain theory and theory about group conflict/threats to provide hypothetical explanations for the observed changes in attitudes.</p>