A scenario workshop taking up the new Organ Transplant Bill as the subject was carried out in order to study the method and the effects of using the scenario workshop, a technique for participative technology assessment, in the context of the teaching of science classes (STS education) which are intended to take up the relationship of science and technology to society. The results of a questionnaire survey taken before and after the classes showed an increase in the proportion of students who were highly interested in the new Organ Transplant Bill. There was also an increase in the proportion of students who had higher consciousness of social participation in the revision of the new Organ Transplant Bill. Furthermore, from an analysis of the protocols, it was found that the students were learning from each other, and that discussions proceeded by repeating agreements, disagreements, and questioning, so that an atmosphere conducive to speaking was fostered by using this technique. Therefore, it was shown that, in the teaching of science classes, it is fully practical to use the scenario workshop as a technique for discussion and consensus formation conducted by the students themselves.