From the limited empirical knowledge we have, religion is hardly ever implemented as a dimension of diversity management in German firms. As religion is increasingly important in many areas of law, with regard to world conflicts, the integration of refugees, societal tensions and potentially high religious diversity of employees and customers in globally acting firms, this finding triggers questions why or why not religion is applied as a dimension of diversity management in German companies. We thus discuss pros and cons for considering religion as a dimension of diversity management, arguing that on the one side there are many arguments for employers in favour of considering religion as a diversity dimension, especially arguments grounded on legal regulations, discrimination or effects on performance and resilience of employees. However, on the negative side, attributions of conflict and irrationality connected with religion and employers’ difficulties in collecting a sound database may hamper implementation as a diversity dimension. We conclude with a research outlook.