Abstract: Cost is one of most important aspects of all type of construction. This research has been designed to study the cost performances of Hospital for Advanced Medicine and Surgery (HAMS) Kathmandu building construction project. In this research the proposed work schedule was compared with actual work progress in site and the estimated cost of the work was compared with the actual cost. The responses from a questionnaire survey and review of records from concerned representative were examined to identify the factor affecting the performance of building construction. The factor affecting the performance was identified and presented in various ways for the interpretation. Out of 23 activities, 14 activities got delayed. The total number of days delayed was 16 days out of 80 days. The reasons were low numbers of labors, rain, change in design, deficiency of material, poor working conditions, non-confidence in workers and poor performance of machinery. The quantity of formworks, M25 concrete and steel got exceeded by 2360.72 sqft, 1820.28 cuft and 3561.36 kg respectively due to change in design. The total excess in cost was 1,668,004.824 rupees which was 12.58%of total cost. Effective and efficient training courses for engineers in scheduling, cost, productivity, information systems and management of human resources must be conducted. The study quality and safety would not have been compromised. Good performance of any construction project refers to continuous improvement of the project activities to achieve the project objectives in terms of time, cost, quality, safety and ethics. Further research should be designed to study the construction performances of Hospital for Advanced Medicine and Surgery (HAMS) building construction project based on quality control and safety.