This case study focused on a university teacher-education course that included NOS content. An adapted questionnaire was used to collect quantitative data on 83 secondary science teachers' views about three NOS themes before and after completing the course. Qualitative data were collected from eight of the teachers who were observed teaching during their field experience after completing the course. The teachers' post-course mean NOS scores were statistically significantly higher than their pre-course scores (t (65) =-10.08, p<0.001; Cohen's d = 1.4). Despite the favourable NOS knowledge among the science teachers, low levels of NOS portrayal were observed in their instructional practices. These findings point to some success in explicitly addressing NOS in science education content courses. However, they raise questions about the transferability of teachers' NOS knowledge into their classrooms. The findings have implications for teacher-preparation programmes regarding durability of NOS knowledge.