One of the most important issues in Iran’s road construction projects operated by public-private partnership financing is the financial risk. This research aims to design the financial risk assessment model for these projects. The factors for financial risk assessment were identified using a semi-structured interview with 23 experts. A total of 14 factors were extracted including liquidity risk, market risk, inflation rate risk, interest rate risk, Government stability in planning, the nature of Iran’s capital market, political risk, the way of bank finance for project, price changes at macroeconomic level, changes of expected return rate, credit risk, and exchange rate risk. The interpretive structural modeling (ISM) approach is applied to identify the relationship between the factors and model levels. MICMAC analysis also is used to specify the characteristics of the factors. The results of the analysis showed that among these variables the operational risk of autonomous variable, exchange rate risk and political risk of independent variables and other variables of the model are the type of interface variable. The results obtained by ISM consisted of a five-level model with 14 factors. Model analysis showed that political risk is the most influential variable and liquidity risk, market risk, inflation rate risk, credit risk, project bank financing, expected rate of change and financial performance are the most influential variables of this model.