Construction projects suffer various problems and complex factors such as cost, duration, quality and safety. Construction sector is diverse as it contains, contractors, consultants, designers, owners, and others. The aim of this paper is to identify factors affecting labor productivity at a building construction project. A literature review and factors recommended by experts were considered to categorize the factors. 40 factors, categorized into 5 groups, were analyzed and ranked considering Relative Importance Index. The questionnaires were distributed to Project Manager, Project Engineer, Architecture, and Others (Scheduler, and Estimator). It was concluded, final cost of the projects were higher than estimated cost. It’s recommended to develop human resources through proper and continuous training programs frame a strong assignment, vision and a planned approach to overcome the disturbances on the performance of the construction projects. The discussed factors are expected to assist in completing construction projects successfully.