In the 21st century, education is identified not only as one of the fundamental human rights that ensure the quality of life, but also as a key driver for the sustainable development of society. Therefore, in modern society, the pursuit of knowledge should become a priority and a way of life for every young person. These reasons encourage the analysis and evaluation of the factors that determine the quality of education, because the context of today's Lithuanian and European dimensions of education determines the necessity of ensuring the importance of the quality of education from an early age. This situation presupposes a problematic question of the research: what factors determine the quality of primary education. That the analysis requires quality assurance issues at the primary level of education becomes clear from the analysis of scientific, methodological literature and educational documents, as issues of quality of education at this level are insufficiently researched and emphasized. More attention is paid to the analysis of quality education in the pre-school sector and basic school. On the other hand, it is a very important and timely issue, because primary education is the first stage of formal education, which has important goals and objectives related to the child's educational opportunities, challenges and further development perspectives. In order to collect the research data, a questionnaire survey was conducted, in which 110 primary education teachers working in the country's educational institutions participated. A questionnaire was prepared, in which the essential information blocks related to the quality of education of primary school students were singled out: planning and organization of the educational process, creation of the educational environment, the teacher's personality and his professionalism. During the research, the factors that determine the quality of education of primary school students were analyzed theoretically and empirically. Statistically significant differences were found in the assessment of different factors, pedagogical work experience and groups of teachers with different qualification categories. Keywords: education quality, empirical research, primary school, quality assurance