. One of the underlying factors needing to be considered when offering toll road projects to the private sector is that they must be financially feasible. In the narrower context, the attractiveness of a project is usually measured via NPV or IRR. Accordingly, the issue of determining the correct discount rate or minimum acceptable/attractive rate of return becomes one of the critical issues. This paper presents a systematic computational methodology for determining the required rate of return (RRR) of infrastructure projects based on the total risk approach i.e. systematic and non-systematic risks. The capital asset pricing model and the certainty equivalent method combined with the cumulative prospect theory are applied to estimate systematic and non-systematic risk premium. A total of three toll road projects implemented under build, operate, transfer (BOT) contracts are taken as case studies for application illustrations with individual required rate of return resulted for each project.