Innovation is defined as a process that is fraught with uncertainty. This article's aim is to diminish lack of knowledge of the factors that create uncertainty in innovation processes. The basic thrust of the present argument is that the potential value integral to innovation may or may not be materialized in the future. Given that the future entails uncertainty, it is reasonable to expect that uncertainty is inherent in every innovation process. Uncertainty results from the fact that, on the one hand, events in the future do not follow the course of past events, and, on the other, knowledge of the future is always incomplete. Using a systematic approach to reviewing the literature, eight factors which create uncertainty in processes of innovation were identified, namely: technological uncertainty, market uncertainty, regulatory/institutional uncertainty, social/political uncertainty, acceptance/legitimacy uncertainty, managerial uncertainty, timing uncertainty, and consequence uncertainty.