The Nordic countries have a century-long tradition for cooperation within the area of citizenship law. Since the mid-1970s, however, the Nordic countries have moved in different directions. Today, the Nordic countries represent the entire continuum in European citizenship policies – from liberal Sweden to restrictive Denmark, with the other Nordic neighbors in between. This report reviews the historical development and the current citizenship regime in the five Nordic countries, it provides statistics on the acquisition and loss of citizenship in each country over the past 10-15 years, and it offers a comparative analysis of the divergent development of citizenship law in the 2000s. The concluding chapter discusses possible consequences of the different citizenship regimes and the prospects for strengthened cooperation between the Nordic countries in the area of citizenship law.