The aim of the paper is to present the importance of management and optimization of administrative processes in a company with the support of the Lean concept. The research part deals with the most popular approaches in business process management using lean manufacturing and the methods and tools used to improve production processes within this trend. The case study focuses on the issue of administrative activities and processes in the organization, and on improving these processes by applying the lean concept using project management. It includes an analysis of the selected administrative process, the identification of the various forms of waste in it and a description of achieved results of the improvement in the particular project. This paper presents a new methodology for the application of lean administration tools in the company conditions.