Entrepreneurship education has spread enormously during the last decades, and today entrepreneurship is taught to numerous pupils and students in various disciplines and at different levels of education. Policy makers around the world view entrepreneurship as a key competence to be fostered already at an early stage of education, and an increasing amount of resources are spent on various initiatives in the field. Entrepreneurship research is, however, a heterogeneous field, and, consequently, there are numerous approaches to entrepreneurship education. Little is known about the effectiveness of these approaches, and much conceptual and definitional confusion makes it complicated to compare the different initiatives in the field. This dissertation seeks to remedy this problem. As such, the overarching research question guiding this dissertation is: What effects do different approaches to entrepreneurship education have at different levels of the education system? To answer this research question a categorization model, based on research about entrepreneurship, entrepreneurship education, entrepreneurial learning, and cognitive and non-cognitive skill development, which addresses the diverse foci of different approaches to entrepreneurship education, is provided. In addition, the dissertation comprises three research papers that individually address different approaches to evaluating the effects of entrepreneurship education at different levels of education.