People involved in the development of radical innovations tend to feel a lot of enthusiasm. It has been claimed that, in fact, this enthusiasm fosters the innovativeness. The purpose of this study is to analyse how enthusiasm is created and sustained in this process. The theoretical framework combines the previous literature on champions and enthusiasm‐creating systems. The study analyses enthusiasm in five processes of radical innovation. The results indicate that it is not only champions but also innovation‐development teams who contribute to spreading enthusiasm throughout organizations. Eventually, the enthusiasm also spreads outside to the customers. Five inhibitors of enthusiasm were identified: commitment, engagement, trust, results and help gaps.