General secondary education is the core of the educational system of any country and the basis for successful education at subsequent levels of lifelong learning. Therefore, in order to address the need to transform education in the context of globalization, it is necessary to conduct a comprehensive analysis of its state and conditions of development, identify characteristic trends, assess the effectiveness of the national system of secondary education, taking into account the results of interstate comparisons. The article considers the existing international systems of assessment of the state of secondary education and their application in the internal system of education on the example of such European countries as the Czech Republic, Finland and Estonia. The results of the international PISA education quality survey in Ukraine in 2018 are presented. The study of the quality of the activities of the general secondary education institutions was conducted on the example of the territorial communities of the Lviv region. The results of the participants of the external independent evaluation and state final certification for 2016–2021 were analyzed. In our analytical study, we also used financial indicators that allow us to assess the effectiveness of the use of funds from the state and local budgets. For this purpose, the calculation and comparative analysis of the most important indicators used in modern research by domestic and foreign scientists were carried out, in particular, the average salary of pedagogical workers; average costs per student, average costs per class, average class size, average number of students per teacher, etc. Research results show that the highest number of students per class, the highest number of students per teacher and, consequently, the lowest average cost per student are observed in general secondary schools of the urban territorial communities. As evidenced by the results of the external examination, a higher quality of school education is ensured. Thus, for example, local authorities managing the education system should look for ways to further improve national school education at other levels of budget funding. The use of European experience will help Ukrainian educational institutions to find a way to a certain vision and achieve the goals of the development strategy.