Although the engineering profession has been called “the failed profession” owing to its lack of social closure, engineers have been successful in claiming their area of expertise and specialized knowledge as legitimate areas of research, knowledge, and intervention. In this article, the historical development of engineering professions in Sweden is used as a case of professional development. With the use of primary statistical sources and secondary historical sources, I endeavor to explain engineers’ professional development via coinciding factors such as the expansion and scientific content of lower and higher engineering education, the struggle for power in interest groups and unions, and engineers’ position in what seems to be an ever-increasingly diversified labor market. I argue that the professionalization process for Swedish engineers has fluctuated and that more than one professional take-off (two or even three) has occurred.