Nature of science (NOS) has increasingly been emphasized as an important element in science education. This paper engages in the question of how teachers negotiate different approaches to and contexts for NOS teaching. This exploratory study is part of a three‐year longitudinal project where six in‐service teachers developed and negotiated their NOS‐teaching practices. Pickering's (1995) theory of the mangle of practice is used for the analysis of teachers’ focus‐group discussions. In a mangled practice, school science traditions, policy documents, and students’ and teachers’ expectations and identities are rubbed against each other. As part of the project teachers planned, implemented, and reflected on two NOS activities at different levels of contextualization. The concepts alignment, resistance, and accommodation are used as an analytical tool to understand the processes of the mangle in relation to teachers’ negotiations concerning the two activities during the focus groups. The results of the mangle are presented in relation to a backdrop of three teaching traditions (facts, lab‐work, and discussions) that the teachers’ claim to depart from. The results show how the alignment and resistance of different components of the mangle lead to various accommodations as regards both the activities and the three traditions. The article concludes by discussing how the teachers’ negotiations highlight what becomes possible and what becomes challenging when NOS meets existing traditions, and what this means in respect of possibilities for NOS learning.