Question: What are the Integrated Project Delivery Implementation challenges in construction projects, their interrelationships and their effects on the project time, cost and quality?Purpose: The Purpose of this study is applying an efficient method to determine the most important challenges to IPD implementation in construction industry, and also to evaluate the interrelationships among these challenges and their effects on the project time, cost, and quality.Research Method: This study models available Integrated Project Delivery challengesusing a real case data, through applying Fuzzy Cognitive Mapping technique.Findings: Results show that contractual factors have the major influence compared with others. This shows the significance of paying attention to why project stakeholders must be integrated throughout the project life cycle since early contract documentation stage.Limitations/Implications: This study is limited to the caseselectedfrom Tehran of Iran.Value for authors: This study is significantdue to identifying, classifying and determining the intensity of effects of IPD implementation challenges on cost, time, and quality of construction projects. It results in planning, resolving the challenges, enhancing the quality of constructions and lastly saving the construction cost and time.