Abstract In this study, the perceptions of domain experts who participated in foresight activities on the impact on policy making are examined by conducting interviews and surveys on five previous foresights in Japan between 1996 and 2007. The purpose of the study is to examine how domain experts look at the practice of foresight in general, and perceive its overall impact on policy making in particular, in the setting of Japanese foresight conducted in the past 15 years. There are two tasks for doing that in this study: to know the views of scientists and engineers who participated in foresights on the impact of foresights they participated; and to know the effect of respondent's characteristics on their perceptions on impact. There are two main findings of this study. First, the impact on policy making perceived by domain experts who participated in foresight activities in Japan is not very high. Second, there are different patterns of perception on the size of the impact on policy making depending on ages, organizations, member status during foresight, and science and technology areas, and habit of following the situation in general looking for any impacts after the foresight.