This article presents an in-depth bibliographic study about the creation, principles, evolution, and practices of the lean philosophy oriented to the services sector. More than 70 papers about “lean thinking” – specially with focus on services – have been carefully reviewed. It presents the principles of lean service in an organized way, companies applying lean service, and best practices and tools in the implementation of lean service. It shows that lean service does not have a single or specific model of tools, practices or standards. In fact, it is a mix of tools and practices that must be applied according the situation found to be improved. Despite the lack of a standards and methodology for use in services, its best practices, inherited from manufacturing, when applied to services can generate large economic and financial results, as well as improvement of workers’ behavior. But, like any change process, this study shows that the application of lean in services also suffers resistance. There might be limitations when evaluating lean practices and principles to services, specially those that have not yet been well defined and reported. Other limitations are due to the scarce articles in the literature. However, this research showed that the use of the lean philosophy in services proved to be effective and quite worthwhile. Several cases analyzed presented significant gains and confirmed an increasing and promising future for service companies “thinking lean”.