Poor cost performance is a typical problem in construction projects where few projects were completed
within the original estimated cost. The previous researches (literature) show that up to 90% of construction projects
suffer cost overrun with amounts ranged from 5% to 200%. This paper first utilizes a literature review to identify
cost overrun causes and categorizes such causes based on stakeholder, country, and project type. Secondly, an indepth review was conducted to identify the contractors' cost overrun root causes. Thirdly, contractors' gaps and
shortage of cost management processes have been identified. Finally, guidelines were concluded to resolve the
identified gaps and enhance cost performance. The research conclusions depict that the top five cost overrun causes
were inflation and fluctuation of construction resources, inaccurate cost estimates, poor cost control, poor owners'
financial status, and work scope change. In addition, this research manifests that two top contractors' related cost
overrun factors, inaccurate cost estimate, and poor cost control, were deemed the main elements of the cost
management system. Another major contribution of this research is addressing the gaps in cost management
processes to pave the way for future studies on identified gaps