This study presents the case study on implementation of Lean Kanban manufacturing principles into the existing Agile software development methodology. The aim of this study was to introduce the adjusted Lean principles which were seen as adequate for enhancing project agility (flexibility and adaptability) and to test if these changes consequently result in improved project team performances. In order to investigate possible effects of Lean approach on improved project agility (flexibility and capacity to adapt to changes), data from interviews, daily team meetings and sprint retrospective were examined. Furthermore, team velocity, defects rates and rework rate data were used for comparison of current Agile methodology success and proposed Lean Agile method. Results show that by adding adequate Lean Kanban principles based on needs of project and team, development process was improved. Defect rate notable decreased while velocity increased, mostly caused by Lean practices enabling more realistic effort estimation and optimized work flow. Moreover, team reported that improved visual management tools facilitated communication and made it more transparent, enabling better and faster problem solving and task management. Keywords: Agility; Lean practices; Agile Project Management; Project Performance Improvement