This thesis is focused on investigating absenteeism trends among high school students in the Republic of Croatia by analyzing data from the Ministry of Science, Education, and Youth collected through the e-Matica system. Absenteeism refers to the frequent and prolonged absence of students from school, which can negatively impact their academic success and social integration. The aim of the research is to analyze the amount of high school absences in relation to potentially relevant variables. The study examined the frequency of absences, compared absences among different types of high schools, and explored the relationship between absences and students' age and gender. Furthermore, it aimed to determine whether there are differences in absences based on the county where the school is located. The results showed that absenteeism among high school students has increased compared to previous years. Vocational school students are more absent. Furthermore, it was found that older students, particularly those in higher grades, tend to be absent more frequently than their younger peers. Contrary to expectations, gender did not emerge as a significant factor in overall absenteeism; however, it was observed that female students are more likely to have justified absences, while male students tend to have more unexcused absences. In conclusion, this research confirmed findings from previous studies that also pointed to higher absenteeism among vocational school students and those in higher grades. Contrary to some earlier assumptions, gender was not a significant factor in the total number of absences, though differences in how absences are justified between male and female students were noted. The study concludes with practical advice and recommendations for the prevention and resolution of absenteeism, with a focus on targeted measures for specific groups of students and improving the monitoring and response to absences within the school system.