Three decades ago, Sweden extended municipal and provincial voting privileges to non-citizen residents on the grounds that this would increase political influence, interest and self-esteem among this group of immigrants. Three decades later, in the political and public debate, electoral participation on the part of immigrants is perceived as being substantially lower than for native-born citizens. As a result, questions have arisen regarding the degree to which this may be symptomatic of a larger integration issue. The aim of this paper is to explore the determinants of voting in municipal elections for immigrants—both naturalised and non-citizens, in Sweden, by controlling for a number of socio-economic and demographic and immigrant specific characteristics. More specifically, using cohort analysis, the idea is to study the impact of time spent in the country on the voting behaviour of immigrants, foreign citizens and naturalised over time. Two unique sets of data were used in the research. The 2002, 2006 and 2010 electoral surveys (participation study) all contain information about individual electoral participation in municipal elections. This information is matched to registry data from Statistics Sweden, which also contains information relating to every Swedish resident. From these two sources of information, a database is created that matches voting to individual characteristics. This study analyses 60 thousand immigrants of which 43 thousand are non-citizens. After controlling for demographic and socioeconomic characteristics, the results show that the acquisition of citizenship makes a real difference in the voting odds. Immigrants who obtain citizenship are far more likely to vote than those who do not. Country of birth also makes a difference: Compared to immigrants from the Nordic countries, Europeans and North American immigrants are equal or less likely to vote, whereas immigrants from Asia, Africa and Latin America are more likely to vote. Finally, immigrants’ odds of voting increase as their length of stay in the country does.