The project portfolio expected results are generally affected or influenced by the materialization of risk factors. Therefore, risk management plays an undeniable role in the decision-making process. Project portfolio risk assessment is oriented to provide information on the importance of risks, giving decision-makers the information to support their risk management strategies. In this paper, the ‘Impact Matrix Cross-Reference Multiplication Applied to a Classification’ (MICMAC) approach was used to develop a proposal focused on analyzing the drive and dependence powers of risk factors based on the interdependencies between them. Therefore, the adjusted influence that each risk factor has on the project portfolio considering the shared influence derived from a risk factor on two or more projects can be calculated. Finally, a representative example is provided to illustrate the way in which the proposed model can be implemented and how the results can be analyzed.