The Republic of Croatia has recognized the importance of integrating vulnerable groups through sports activities, aiming to improve the quality of life and raising public awareness of the importance of such activities. The European Union (EU) has provided financial support to Croatia through the European Social Fund (ESF). Within the financial envelope for the programming period 2014 - 2020, the ESF allocated 64 million kuna to finance activities involving the inclusion of vulnerable groups in sports, specifically children and youth at risk of social exclusion, persons with disabilities and children with developmental difficulties. Based on the implemented contracts, there was a recognized need for further funding of sports activities for these target groups, hence the ESF has additionally provided for the financing a new call for funding for these vulnerable/target groups in the next financial period, 2021 - 2027. The specialist thesis explores the legal framework of the European Union and the Republic of Croatia concerning the definition of vulnerable groups, as well as the necessity for their inclusion in society. The objectives and purpose of the ESF was analysed, along with the principles of effective project management funded under that EU fund, while the main part of the thesis contains an analysis of project documentation and research results on the management and implementation of projects based on the completed ESF call “Inclusion of children and youth at risk of social exclusion and persons with disabilities and children with developmental difficulties into the community through sports”. The aim of the conducted research is to develop recommendations on how team leadership and project management can be made more effective and efficient within these specific program initiatives, thereby contributing to increased social inclusion of the target group, i.e., vulnerable groups. The paper also explored the elements of collaboration among different stakeholders that are crucial for successful project management and implementation, as well as how the education of team members working with vulnerable groups can impact on project outcomes. The conclusion emphasizes the importance of projects with these project activities, as well as recommendations for more effective project management that contribute to higher quality of project outcomes and future sustainability, which is the most crucial need of vulnerable groups.