This research investigates Finnish teachers' personal worldviews, by focusing on understanding what kinds of approaches teachers use concerning the visibility of their personal worldviews in an educational context. This issue is discussed in the light of teachers' professional autonomy and ethics, since these are two fundamental dimensions of teacher professionalism that are discussed a lot. The research was conducted using a qualitative attitude approach, and included interviews (N = 20) from Finnish in-service basic education class teachers. The results show that teachers use three different approaches where their personal worldview and its visibility in their work are concerned. When reflecting on worldview questions, there was uncertainty about balancing between practicing teacher autonomy and following teachers' official responsibilities. Teachers' personal worldview expressions were limited to the institutional worldview, which means in practice adopting norms and language of the worldview majority, and professional ethics was highlighted even more than autonomy when reflecting on the visibility of worldviews.