Despite pressing concerns about the need to prepare high-quality teachers and the central role of teacher educators (TEs) in this process, little is known about how TEs teach about teaching specific subject matter, and how they develop their expertise. This empirical study focuses on the specific expertise that science TEs bring into teacher education. Individual interviews and story lines were conducted with 12 experienced science TEs from four different teacher education institutions in Australia and the Netherlands, to gain insight into their aims for teaching about science teaching, and how their expertise has developed on the basis of their professional background and experiences. The findings of this exploratory study reveal similarities among the concerns of these TEs and yet considerable diversity among their approaches. The study aims to contribute to a better understanding of science TEs work and the development of a pedagogy of science teacher education.