This paper aims at identifying and examining the most influential factors affecting the productivity of maintenance labor, with a focus on the electricity industry of the United Arab Emirates. To achieve this objective, first, 34 factors have been identified from three sources: a comprehensive literature review, researcher non-participant observations during the performance of maintenance tasks, and semi-structured interviews conducted with two experts from the maintenance field in the UAE electricity industry. Second, a statistically representative sample of employees handling maintenance activities within the UAE electricity authorities has been invited to participate in a questionnaire-based survey in which the 34 identified factors have been evaluated. This study has revealed that the following five factors, ranked in descending order, are the most significant in their effects on maintenance labor productivity in the UAE electricity industry: (1) skill level of labor; (2) health condition; (3) availability of tools and equipment; (4) safety measures; and (5) weather conditions (high temperature). These results can be very useful for decision makers in the field of maintenance and in particular in electricity industry to better manage their human resources and improve their productivity.