A modern digital society pervaded by technology, imposes requirements for the technological upgrading into all spheres of the society simultaneously affecting also the educational system. Under that fact, in this paper titled „The advantages and Disadvantages od E-register and its Use in Educational Practice“, the aim was to study fully the extent to which information and communication technology entered the area of education, the way how the system of education responded to ICTs' requirements trying to understand also in what way has ICT affected the main participants in education: students and teachers. Teachers of almost every high school in the city od Zadar area that use E-register were surveyed for the purpose of the thesis. The main objective of the research was to learn what are advantages and disadvantages of the use of the E-register application in the education highlighted by 127 surveyed teachers while examining the opinions of teachers on their own development of competences and skills for using ICT. The paper also seeks to examine teachers' opinions on upgrading an educational system by integrating the modern information and communication technology into existing educational practice and to examine the teachers' perceptions about the possible changes in learning and teaching in a new digitally-resourced society. The collected data established that the E-register application has been successfully implemented into the educational system whose effectiveness in use has also been confirmed. There is always enough space for progress, so the applications' upgrades should be focused on the advise provided by teachers in this paper.