As many developing countries adopt a PPP BOT model to encourage private investment, some PPP projects may be economically viable but financially unfeasible unless viability gap funding (VGF) is provided. This research explores the fiscal implications of such government’s VGF support in multiple PPP toll road projects. In this study, three PPP toll road projects in Bangladesh were adopted as the case study projects. They were financially analyzed to determine their net present value (NPV) and financial internal rate of return (FIRR). The negative NPV of the project indicates that the project needs VGF, but the maximum or the minimum VGF to be given may be based on the negotiation between the private and the host government under its PPP laws and guidelines. After determining the minimum VGF, the fiscal impact of the collective VGF was compared with the 2023–24 fiscal budget, focusing on transportation and other key sectors. It was found that the total VGF required would be around 0.05% of the total fiscal budget if provided as a one-time grant, or 0.03% if distributed equally as an annuity over the first three to 4 years of the construction period. This approach helps the government to estimate the additional budget required for VGF support, while it is also aiding in strategic decision-making regarding budget allocations and VGF policies.