In an era where there is increasing immigration and increasing diversity, and concomitantly, a policy era where countries in North America and Europe seek to tighten citizenship acquisition rules, it is important to understand the social, economic, and legal implications associated with naturalization. The goal of this special issue is to explore citizenship issues across a broad range of both countries and issues. The five papers in this issue are drawn from a 2-day conference on citizenship issues held in Malmo, Sweden in May of 2009. The conference, co-funded by the International Migration Integration and Social Cohesion project and Malmo Institute for Studies of Migration Diversity and Welfare brought together a multidisciplinary group of researchers from Europe, Canada, and Turkey to share research on the implications of citizenship acquisition at both the micro and macro scale.