The article examines the features of assessing the reliability of investment projects. The key aspect that the authors consider it appropriate to highlight in the process of methodological substantiation of the effectiveness of investment projects is the assessment of reliability, determined through sensitivity analysis. Being a method of quantitative analysis, the analysis sensitivity allows us to identify the level of the project's response to variations in price, costs or other parameters, signaling the possibility of occurrence or absence of risk. If there is high sensitivity to changes in one or another factor, we can talk about absence of project reliability, on the contrary, if the sensitivity is low, then the project has a fairly high reliability. The authors consider it an important task to determine the parameters relative to which it is necessary to determine the safe dynamics, i.e. the growth rate of the parameters investment projects that do not result in unprofitable investments. For this purpose, it is proposed to calculate «dynamic norms» – a direct numerical expression of safe dynamics – relative to two parameters. Determining the values of these parameters at the stage of designing monetary flows allows you to make adjustments at the initial stages to increase attractiveness by expanding the safe dynamics interval. Among the advantages of this method, the authors highlight the establishment of clear boundaries in conditions of uncertainty in the dynamics of the following monetary flows, which increases the level and quality of monitoring and control. Among the disadvantages is that when assessing projects with high volatility of cash flows, the methodology may not be suitable. Thus, the use of reliability assessment in the system of sensitivity analysis of investment projects will allow to minimize risks when making decisions on the feasibility of investment.