In this article the focus is on the specific variant of psychology of work which Kurt Lewin started to develop during the 1920s in Germany andafter his flight from Nazi Germany to the USA in 1933-returned to in the late 1930s, in an American industrial setting. The central questions are: did Lewin's approach comprise an adequate theoretical framework for studying the problematics of the work process concerned? To what extent did it constitute a control device for management? After an overview of Lewin's activities within this field, both in his Berlin period and his American years, a critical analysis of his approach of action research in American industry is given. From an emancipatory perspective on the psychosocial sciences, this leads to a negative appraisal of Lewinian action research as to its "democratic" yet manipulative tendency. In this respect a discontinuity is discerned in comparison with his early thoughts on psychology of work. In addition suggestions are given for a more adequate conceptualization and research strategy with regard to the study of the work process.