Lean ideas have been used in the business world for some time. Lean advocates have been adapting these principles to different industries, including construction. The main principles of lean processes include value added to the customer and elimination of waste. It is very important for the owner to get the project completed on time, but that is a contractual requirement. Minimizing time waste and delivering projects “ahead of schedule” would be an added value to the customer. Some construction companies have successfully adopted Lean principles to manage their projects while others have not. The objective of this study was to determine the impact of Lean principles on timely completion of construction projects. In this study, projects with Lean strategies versus non-Lean strategies were compared to analyze the impact on their completion schedule. A survey was conducted with project managers of construction companies to collect data on project completion and Lean tools that are typically used. Results indicated that application of Lean principles assisted contractors to complete projects ahead of schedule, or helped them catch up to finish on time when delays were encountered. This study is intended for those general contractors who are skeptical of Lean practices and would like to see examples that Lean can help them deliver projects faster and more efficiently.