Understanding how to mitigate project risk is an important aspect of project management. Risks that are not properly managed can lead to cost overruns, schedule delays, wasted manpower and effort, and failure of the project artifact. Deciding which risk mitigating actions to pursue has largely been an intuitive endeavor, relying on expert opinions which are typically opaque. A more quantitative approach, based on results from actual past projects, is needed. This paper presents empirical findings relating past risk mitigating actions and project outcomes such as project cost, project schedule, and project risk. The findings are based on analysis of a legacy archive of project risk and risk mitigating actions from a large design organization, as well as from categorizing the different types of actions found in the archive based on a taxonomy developed using the archive itself, and analyzing the outcomes of those different types of actions. This study presents a more quantitative understanding of the relationship between a project state, the risks involved, and risk-mitigating actions taken during the project. This will enable improved decision making with better knowledge of the possible consequences of different types of risk mitigating actions and their effects in decreasing project risk. . © 2013 The authors. Published by Elsevier B.V.