This is a cross-cultural comparative study that sets out to explore teachers' knowledge, understanding and practices of the teaching of Physical Education (PE) to students from different cultural backgrounds. More specifically, it explores key issues in the teaching of PE to Muslim students. Thirteen PE teachers, six from England and seven from Greece were involved in face to face interviews exploring issues related to the teaching of PE to culturally diverse classes, their subject matter knowledge, pedagogical knowledge and knowledge of students' religion and culture. The findings suggest that teachers had a limited knowledge of their students' culture and religion. More specifically, "novice" teachers with modest cultural knowledge faced difficulties in teaching students from culturally diverse backgrounds. The study stresses the need to increase student teachers' knowledge and understanding --as part of their initial teacher education courses--to respond and operate effectively towards wider inclusion of students from ethnic/culturally diverse backgrounds in PE and extra-curricular activities (ECA).