Cohesion policy is the European Union's main investment instrument, and as such makes up a large part of the EU budget. It seeks to promote the general development of the European Union by reducing disparities between the levels of development of the Member States and the regions. Cohesion policy is implemented through five separate funds that support smart, sustainable and inclusive growth. Urban centers - cities - play a key role in promoting sustainable development. Based on the Decision on the selection of the area for the implementation of the ITU mechanism, the City of Zagreb was selected as the urban area for its implementation. The project Technical Assistance to the City of Zagreb for the implementation of the ITU mechanism provided capacities for the implementation of all activities and related tasks in accordance with the prescribed legislation. The emphasis of this paper is placed on the success of the establishment of the system of intermediary body for the implementation of the ITU mechanism and the contribution of the application of the territorial approach to the development of the City of Zagreb. Since 2016, the City of Zagreb, as the center of the urban agglomeration, has begun the process of introducing integrated territorial investments, asking the gravitating cities to submit their project proposals. In the urban area of the City of Zagreb, eight projects have been registered by the end of 2020. The analysis of applied and contracted projects has established that integrated urban management is possible through a combination of key resources, and they seek to meet the goals of improving the quality of life, human resources and infrastructure. Also, the paper emphasizes the potential of the applied projects in the form of economic development and environmental protection.