Objective This study investigates inequalities in the distribution of citizenship status among immigrants in Canada and the United States between 1970 and 2001. It is motivated by a desire to probe deeper into the gap in citizenship rates between the two countries. Methods Logistic regression analysis of census data is used to predict the odds of citizenship among the foreign born, controlling for a range of factors. Results There has been a growing inequality in the distribution of citizenship in the United States, but not in Canada. Low rates of citizenship hide the appearance of a large disparity in citizenship between those with the lowest levels of education and everyone else. These results cannot be entirely ascribed to the presence of undocumented immigrants. Conclusion Persistent and large inequalities in citizenship leave the already disadvantaged unskilled immigrants without access to rights, representation, security, or job and educational opportunities.