Utilizing a large and unique dataset composed of government records, we study the widely contested effect of co-ethnic residential concentrations on voter turnout. Non-Western immigrants are moderately affected by the concentration of co-ethnic voters in their neighborhoods. As the local concentration of same-ethnicity voters increases, so does the individual's propensity to turn out for the election. In general, the concentration of non-Western immigrants in the neighborhood has only a very limited impact on an immigrant's propensity to vote. Finally, we investigate the possible mobilizing effect of local candidates and, in particular, local co-ethnic candidates on voter turnout. We find that the presence of candidates in general and co-ethnic candidates running for office in a neighborhood has a moderate positive mobilization effect. However, taking this factor into account, the effect of residential concentrations was not eliminated.