Recruiting police officers with immigrant backgrounds has a limited effect if many of these recruits leave the police service. The dropout and attrition rates among officers with immigrant backgrounds are also an important indicator of the challenges this group faces when joining the police profession. We investigated police education dropout patterns and attrition rates among police students and officers with immigrant backgrounds. Our study is based on detailed longitudinal data with total coverage of the population, which were previously unavailable for police career studies. Using logistic regression and coarsened exact matching, we analysed administrative registry data covering all individuals admitted to the Norwegian police university college (1995–2010, N = 6570) and all police-educated staff employed in the Norwegian police (1995–2014, N = 7001). Students and police officers with non-Western immigrant backgrounds have a greater tendency to both dropout of education and leave the police service. Prior academic performance can only partly explain these higher educational dropout rates. Female and males with non-Western immigrant backgrounds have similar dropout patterns. Our results provide a rationale for developing policy aimed at not only recruiting, but also retaining police officers with immigrant backgrounds.