The application of lean concepts is a practice originated in the automotive industry initially used in manufacturing areas, enabling productivity gains by reducing waste in the process flows. After the proven success of using lean in manufacturing areas, organizations have expanded the use of this concept to other areas. The aim of this work is to apply the lean approach in the review of the flow of materials from a warehouse in equipment s manufacturer for the oil and gas sector. The methodology used has two components: a systematic review of literature on the lean concept and action research through a protocol based on a proposed model for application of case studies on action research. This dissertation describes the lean application process. The results achieved to date demonstrate the feasibility of the application of lean principles in the warehouse, identifying the value stream and 5S as the main implementation tools, and a significant reduction in warehouse s flow lead times. Barriers were found as competition of people s time between action research and their routine activities and the low initial involvement of sectors interfacing with the warehouse (eg, planning, purchasing and production). A proposal based on the map of future value stream to the flow of materials in the warehouse, migrating from traditional pushed to lean model, was presented to the company and is being considered for implementation.