Focusing on diversity and diversity policy within organisations in general and within police forces in particular, diversity in uniform presents various themes: a conceptual exploration of diversity, an analysis of diversity and relevant research within European police forces and a comprehensive comparison of the regional police forces in Catalonia and Utrecht. As such, Anne R. van Ewijk has made an inspiring contribution to the fi eld which is aimed at all researchers and public or private policy-makers that are interested in diversity. First of all, she provides an analytical framework that identifies fundamental choices in the defi nition of diversity (the 'what', or the ontological dimension), in the motivation for diversity within organisations (the 'why', or the deontological dimension), and in diversity policy as an organisational strategy (the 'how', or the instrumental dimension). Second, she provides an overview of empirical data on diversity within police forces in Europe, identifies important research gaps in the fi eld, and proposes a comprehensive view to structure future comparative research. Finally, she compares two regional police forces (the Mossos d'Esquadra in Spain and the Politie Utrecht in the Netherlands) and shows similarities in defi nitions and motivations for diversity, but differences in approach. In doing so, she demonstrates the academic potential of the analytical framework by applying it empirically, and confi rms that diversity and diversity policy are multilayered concepts in theory and in practice.