Abstract— to identify the major causes of delays on construction projects in India; the major causes of delays from this research study were investigated following data collection carried out through a questionnaire survey with a wide range of construction professionals based in Underground Projects. The findings from this research determined the major causes of delaysbased on an importance index, and the main conclusions from output of the data could help the construction sector to better assess not only themajor causes of delays o n construction projects but also how tominimize them by proper planning. There may, however, be opportunities for safer working practice arising from new awareness of health, hygiene, and safety risk. The role of safety leadership is overlooked in guidance yet is vitalto ensure safeapplication of working practices.In the present scenario, apart from addressing the increasedrequirement Delay factors can be minimized by proper decisionmaking throughout the construction process but further research is required. This could include research into the communication of decisions, the content of training programmes for construction site managers, the value of apprenticeship schemes to provide a more skilled workforce, the possibilities of greater use of pre-castmaterials etc. this study identified the causes of delays onconstruction projects in India during pandemic.As Underground projects are much essential part of city, it needsto be completed at earliest for public benefits. Almost allUnderground projects in India are facing delay. Delay is generally considered as the most common, complex and risky problem encountered in construction projects. Most construction projects in developing countries are characterized by overruns in time. All projects, regardless of size, complexity are burdened by deadlines and uncertainty. Delays occur in every construction project and the magnitude of these delays varies considerably from project to project. This research carries out a detailed reviewof the previousstudies of the time and cost overrun factors.Keywords- Delay, Underground, Cost, Time, budget,Management, Risk Management, Planning, Quality, Schedule