Although traditional project delivery system is one of the project delivery systems that is preferred by both public and private owners, characteristic of the system constitutes some barriers in achievement of the project goals. In the scope of this study the barriers caused by traditional project delivery system were revealed for achieving the basic project goals which are quality, time and cost. For this purpose impact of the relationships between the participants and workflow process of the system were examined in achievement of the quality, time and cost goals of the project. It is found out that impossibility of contractor`s involvement to design process, adversarial relationships among the participants, impossibility of using fast track and uncertainty of final project cost because of the unexpected project changes are the main barriers that have impacts on main project goals.