This article reports on research in the Netherlands to determine the distinctive characteristics of powerful workplace learning environments within primary teacher education. Nationally and internationally, educational competence- based models and so-called workplace learning environments are widely seen as promising alternatives in professional teacher education. The workplace learning environment as defined by Geldens (2007) consists of one or more Professional Development Schools and (almost always) one university for professional teacher education. It is a logical consequence of her notion that the only way to provide highly qualified teaching professionals is by means of collaboration between a university of teacher education and one or more Professional Development Schools. The main purpose of the research was to obtain a coherent representation of the characteristics of workplace learning environments for primary teacher education. A second purpose was to gain insight as to the characteristics that make learning how to teach in a workplace learning environment ''powerful.'' A third purpose was to gain insight into the structure and content of mentoring conversations within the workplace learning environment.