<p>Public-private partnership (PPP) projects are characterized by a high degree of uncertainty and are frequently subject to competitive pressures. Such projects entail the participation of both the public authority and the private entity (commonly designated as the concessionaire), the latter of which frequently encounters challenges in assessing the appropriateness of undertaking investment within the PPP framework. Consequently, it requires a suitable mathematical framework to assess the economic viability of these projects. Furthermore, a potential private competitor may decide to invest and participate in the project, making the strategies to be adopted by individual subjects even more complex. This study proposes a Real Options Game approach to assess the impact of competition between the concessionaire and another private firm on the decision to participate in public-private PPP projects. Within a Cournot game framework, the proposed model combines real-options concepts with game theory, incorporating the key features that characterize PPP projects. Among these are their sequential nature and the abandonment option with a salvage value that may be available to the concessionaire. This study contributes to the scientific literature by proposing a mathematical model capable of evaluating PPP projects while accounting for uncertainty, sequential decision-making, competitive interaction, and the abandonment option with a salvage value.</p>