Teaching about nature of science (NOS) within a science curriculum that is primarily concerned with developing scientific content continues to provide a challenge for teachers. This study of science lessons focuses on whether NOS is being incorporated implicitly or explicitly, and whether epistemic aspects (e.g. models, theories) and social aspects (e.g. controversies, ethics) are addressed in a range of topics. The study raises questions around how teaching NOS can remain on the agenda in a content-heavy curriculum and how it can be important to the reality of multicultural classrooms.