AbstractOffsite construction has been shown to possess many advantages and benefits in dealing with the construction industry’s challenges, which include poor labor productivity. Nevertheless, all previous productivity-related research studies have focused mainly on factors impacting labor productivity in traditional stick-built construction methods. This paper filled this knowledge gap by following a multistep interrelated research methodology. First, a research team of 19 construction professionals and academics developed and distributed an industry survey to (1) quantify the likelihood of occurrence and relative impact of risk factors that adversely impact labor productivity in offsite construction projects; (2) identify and prioritize key risk factors that adversely affect labor productivity in offsite construction operations; and (3) examine how labor productivity risk factors are perceived by various project stakeholders. Second, different statistical analysis tests and methods (i.e., internal and external reliability, statistically significant differences, clustering analysis, and concordance analysis) were used to critically analyze the results and draw conclusions. Based on a total of 100 responses and 20 labor productivity risk factors, the findings reflected that the top five risk factors adversely affecting labor productivity in offsite construction projects included (1) unskilled labor and improper workforce training and development; (2) poor logistics; (3) errors, omissions, and rework; (4) work area congestion and overcrowding; and (5) insufficient coordination. Also, the findings indicated that labor productivity factors can be clustered into two groups: factors with high overall risk and factors with low overall risk on offsite construction labor productivity; 80% of the risk factors were found to fall into the first category. The results of this study also reflected the need for offsite construction companies and industry practitioners to carefully establish mitigation plans and corrective actions for the identified key risk factors adversely affecting offsite construction labor productivity. This study adds to the body of knowledge by exploring and ranking productivity factors in offsite construction projects. Ultimately, this study will help the industry and research communities better understand factors affecting offsite construction labor productivity, more effectively direct future efforts to enhance labor performance, and devise productivity improvement strategies.