This paper investigates how ethnic diversity, measured by the immigrants' countries of origin, influences the well-being of the host country. Using panel data from Germany for the period 1998 to 2012, we find a positive effect of ethnic diversity on the well-being of German citizens. To corroborate the robustness of our results, we estimate several alternative specifications and investigate possible causality issues, including non-random selection of natives and immigrants into regions. Finally, we explore productivity and social capital as potential mechanisms behind our finding.