In the context of current trends in the development of project management, the effective use of agile methodologies allows to improve the quality of decisions made and optimize resources in achieving the set goals. The relevance of the topic is due to the need to adapt traditional approaches to project management to the realities of agile methodologies. The article considers approaches to determining the specifics of forming a KPI system when assessing the success of projects. The key principles of forming indicators are identified, the author's KPI system is developed, and recommendations for its implementation in organizations are proposed. Object of the study: performance indicators used in project management using agile methodologies. Object of the study: to develop theoretical approaches to forming key performance indicators when assessing the effectiveness of processes, products and teamwork within the framework of agile methodologies. Research methods: theoretical analysis, abstraction, generalization, tabular and graphical methods, modeling. Scientific novelty of the research: the research contributes to the development of the theoretical basis of project management. The proposed KPI model helps to improve the efficiency of project management, and also provides the possibility of their application in a wide range of flexible methodologies. The results of the research can be used to optimize project management processes in organizations focused on the implementation of flexible methodologies.