Contractors want to improve the construction productivity and utilize an efficient, cost calculation which assists the company to get accurate cost that can be presented during next estimation for similar construction projects. This study deals with the application of Value Stream Mapping (VSM) as a lean construction tool on a real construction for installation of underground pipelines. VSM was adapted to reduce the high percentage of non-value added activities and time wastes during each construction stage, and the study searched for an efficient, way to consider the cost of e the studied underground pipeline. This review is unique in its approach that it adopts cost implementation of VSM to improve the productivity of underground pipeline projects. A real construction project was observed and relevant data were collected from the site during construction, indicating the value added, non-value added and process time for each construction stage. The current state was built based on these details. This is a process management tool and exercise to keep opening eyes as a trigger for improvement. After a current state assessment, a future state is attempted by value stream mapping tool balancing the resources using a line of balance (LOB) technique. This study is unique in its way that it adopts cost and LOB implementation of VSM to improve the productivity of underground pipeline projects. Moreover, a cost estimation model was developed during current state and future state to calculate the cost of constructing the underground pipeline. The results show a cost reduction of 20.8 % between current and future states. This reflects the importance of the cost based value stream mapping in construction as a useful tool. This new tool could be utilized in the construction industry to improve the efficiency and cost management.