The aim of this study was to examine the determinants of school success, i.e. to determine the predictability of demographic variables, online learning experiences and psychological distress in the period of the COVID - 19 pandemic, in explaining success in state matura exams. The research was conducted on 3755 students in the final grades of secondary schools in the Republic of Croatia (70.3% female) who took the state matura exam in the summer term of the school year 2019/2020. Data were collected by an online questionnaire from the National Center for External Evaluation of Education as part of a larger online learning survey. which examined demographic data and distance learning experiences. psychological distress was examined with the CORE-YP scale. As a measure of school success, results from the basic and higher levels of Croatian language and Mathematics at the state matura were used. The data were analyzed by hierarchical regression analyzes and the highest percentage of success in the state matura exams can be explained by demographic variables, of which attendance at grammar school is the best predictor for all exams. In addition, schooling in a place with a larger population is a positive predictor for most exams. Also, males have better success in all exams except for the higher level of the Croatian language where females have higher success. Furthermore, lower psychological anxiety significantly predicts success at the higher level of Mathematics and the basic level of the Croatian language although the contribution to the Croatian language is very low. Also, lower satisfaction with teaching and lower perception of the effort invested in distance learning predict better success in the state matura exams.