Reliable productivity rates for construction trades are essential for contractors to accurately estimate the time and cost of construction projects. These rates vary considerably based on the complexity of the structure, project site constraints, and other technical, managerial, social and cultural factors. Predicting the effect of these factors will enhance the ability of the contractor to optimally utilize resources. This research therefore aims to evaluate the most significant factors that affect productivity of key construction activities namely: excavation, formwork, reinforcement, concreting, blockwork, plastering and tiling. The research focuses on the construction industry in the UAE (United Arab Emirates).