This paper focuses on teachers of secondary level religious education in England, Estonia, France, Germany, the Netherlands and Norway. It presents a study of the teachers' perceptions of and responses to the diversity within their classes, in relation to their professional role and their personal and professional biographies. The study employed biographical research methods and 36 teachers were interviewed. Key findings were that, in every country, there was a clear relationship between individual teachers' personal biographies and how they responded to religious and/or cultural diversity and common cross-national strategies for dealing with these aspects of diversity. However, socio-cultural factors within each country (including dominant views of the relationship between religion and education) affected the ways in which the teachers perceived the diversity within their classes and there were national differences in how teachers prioritised aspects of diversity. The study concludes that if teachers of religion are to extend the range of their responses to classroom diversity, they would benefit from opportunities to reflect on the relationship between their perceptions of and responses to religious and cultural diversity, their personal biographies, and national requirements and expectations related to their professional role.