This research explored the concept of top management team (TMT) certainty, that is, the degree of confidence that the TMT has about its environment assessments and subsequent strategic decisions. Using a banking simulation, this exploratory study suggested that beliefs about the environment and a strong team orientation were critical determinants of TMT certainty, while actual environmental volatility and consensus within the TMT were not. Additionally, the research explored the positive relationship between TMT certainty and organizational performance.