PurposeAs managing risks effectively is critical for successful projects, project managers regularly identify and prioritize the risks that apply to their projects. However, research argues that project managers struggle to identify effective risk mitigation approaches for the most critical risks, partly because they do not always have the required authority to act effectively. The authors argue that, particularly in high-risk projects, organizational support (OS) provided by senior executives to project managers can facilitate a practical approach to risk mitigation beyond traditional risk management practices.Design/methodology/approachThe authors modeled the relationship between risk, organizational support and project success. Then, the authors conducted a structural equation modeling analysis on survey data obtained from 722 projects and tested for the impacts of OS practices in the presence of risk on projects' success.FindingsSuppose done effectively, senior executives can provide more support to project managers and the teams in high-risk projects, resulting in higher project success. OS has a positive impact on project success in terms of efficiency and effectiveness. Interestingly, the positive impact of OS on success is greater than the negative impact of the risk.Practical implicationsThe paper further describes various effective OS practices to mitigate risks and explore opportunities when faced with high-risk projects.Originality/valueWhereas it is known that risk has a negative impact on project success, this paper suggests that, in addition to that, OS is in between risk and success and has an impact on this relationship (mediation). Moreover, with OS, the total negative effect of risk on effectiveness turns into a positive impact.