The article substantiates the necessity of extension and development of tools for methodological evaluation of effectiveness of public-private partnership (PPP) projects both individually and in comparison of effectiveness of various mechanisms of projects realization on the example of traditional public procurement. The author proposed an original technique of modelling cash flows of private and public partners when realizing the projects based on PPP and on public procurement. The model enables us promptly and with sufficient accuracy to reveal comparative advantages of project forms of PPP and public procurement, and also assess financial effectiveness of the PPP projects for each partner. The modelling is relatively straightforward and reliable. The model also enables us to evaluate public partner's expenses for availability, find the terms and thresholds for interest rates of financing attracted by the partners and for risk probabilities to ensure comparative advantage of PPP project. Proposed criteria of effectiveness are compared with methodological recommendations provided by the Ministry of Economic Development of the Russian Federation. Subject: public and private organizations, financial institutions, development institutions and their theoretical and practical techniques for effectiveness evaluation of public-private partnership (PPP) projects. Complexity of effectiveness evaluation and the lack of unified and accepted methodology are among the factors that limit the development of PPP in the Russian Federation nowadays. Research objectives: development of methodological methods for assessing financial efficiency of PPP projects by creating and justifying application of new principles and methods of modelling, and also criteria for effectiveness of PPP projects both individually and in comparison with the public procurement. Materials and methods: open database of ongoing PPP projects in the Russian Federation and abroad was used. The following methods were applied in the research: general scientific theoretical methods, such as idealization and formalization; general scientific experimental methods, such as modelling of objects under study. Results: the main result of this research is development of modelling for comparative analysis of PPP projects and traditional public procurement. This enables us to estimate the “price-quality” ratio and, based on it, analyze critical parameters of the project. Conclusions: despite the objective complexity of the analysis of effectiveness of PPP projects both individually and especially when compared with traditional forms of public procurement, there is a relatively simple way to perform such an analysis by means of modelling and comparison of cash flows of all parties of the PPP process. Proposed model makes the criteria for PPP projects effectiveness more intuitive for interpretation while preserving all key parameters. The relative simplicity of the analysis, calculation of limiting values, and interpretation of the results make the model a useful practical tool both for bodies of the public sector and potential private investors.