This research was undertaken to develop a user-friendly, systematic management tool to understand and assess the key risks specific to PPP power station project with the ultimate goal of improving project performance. The study develops a conceptual risk assessment system (RAS) using combined risk map and fuzzy sets theory for assessing PPP projects risks. The proposed system has then been applied to a PPP power station project in Iran in order to demonstrate its effectiveness. The combined risk map and fuzzy sets theory approach is very effective to assess project risks across project, work package and activity levels. According to risk relative importance values, the extreme risk level ranked ones (out of 68 risk items) are assumed as an appropriate way to represent the key risks. In one hand, the conventional project risk assessment frameworks emphasize on managing business risks and often ignore operational risks. On the other hand, the studies that deal with operational risk often do not link them with business risks. However, they need to be addressed in an integrated way as there are a few risks that affect only the specific level. Hence, this study bridges the gaps.