This paper consists of three main parts, of which the first two parts – State Administration and e – Administration serve as an introduction to the third, most important part – the e – Citizens system. In order to even understand how important and unavoidable a component of everyday life is for almost half of the population of Croatian citizens, foreigners and digital nomads, it is necessary to understand the very concept of state administration, and thus e-administration as its response to the increasing digital connection between the administration and citizens. Today, it is almost impossible to remember life without quick, simple and functional access to the many e-services that are offered, which have replaced most of the paperwork, waiting in lines, overcrowded with the work of civil servants and the lengthy process of obtaining all the necessary documents that are crucial for inclusion in life, work, business, family, education, etc. The third part of the paper explores in detail the topic of this paper, and is divided into several sections in order to facilitate an overview of what exactly the e-Citizens system is, when it was created and why, the redesign that occurred in response to the greatest possible need of the population for various services, the way of using the e-Citizens system, its main components from NIAS (National System for Electronic Identification and Authentication of Users), the type of credentials, the level of security and the catalogue of services available to citizens on the portal. e – Citizens is a system that has revolutionized modern administration and facilitated communication and data exchange between the state administration and citizens. How important it is is also shown by research on how many users use the services of e-Citizens and how unthinkable it is to imagine a modern administration without e-Citizens.