Productivity is a very challenging aspect and momentous concern in construction industry because it controls the overall project performance. Complications are typically related to the labour performance. In the construction sector, there are several internal and external aspects that are variables and are terribly troublesome to predict. Also, this results to never-ending deviation in productivity of labours we tend to come through at sites, so it’s momentous to assure decrease in productivity doesn't cause time and cost over runs in the project. Besides these challenges rehabilitation projects get even complex due to various parameters such as ageing, fire mishap, overloading etc. There are numerous prerequisites involved before initial assessment of rehabilitation projects which in turn sometimes add to time delays and quality control. Rehabilitation projects needs to identify parameters resulting in decline of productivity and address these factors in order to enhance the performance of the project. To address this, the current study aims to identify and analyze the critical factors influencing labour productivity in building rehabilitation projects. For doing so, factors that affect labour productivity are identified from the literature (secondary sources) as well as from case studies (primary sources) are clubbed to form a comprehensive list. The identified factors are analysed using statistical tools to obtain the critical factors influencing labour productivity of rehabilitation projects on site using questionnaire surveys and suitable recommendations are proposed to improve labour productivity using the acquired results. According to the results of an examination of 50 identified factors, the significant factors affecting labour productivity are: Design complexity due to uncertain nature of projects, Inefficient crew composition, Missing design information, Unavailability of relevant guidelines and methodology, Lack of contractor expertise for rehabilitation work, Large distance between material storage and work location, No space to keep enough material near work location, Inexperienced or unskilled worker, Site congestion and obstructions, and Degradation of undamaged materials and equipment during rehabilitation works. The project team will be able to improve onsite labour management and overall project performance by prioritising these factors that affect labour productivity.