This work is a study of convergent pattern of mixed methods research that combines quantitative and qualitative research methods to assess teachers' and students' opinions about the reasons of secondary education students' absenteeism in Europe and Turkey. The study sample is 10 teachers (two from each country) working in high schools in Turkey, Iceland, Austria, Czech Republic and Spain, and 155 students studying in those schools. The sample group was determined by using purposive sampling technique. The data collection tool applied to 155 students is the "The Scale of Absenteeism Causes" which is 5point Likert type and consists of 34 items and 4 dimensions. Also, semi-structured interview form was applied to these 10 teachers. Percentage, mean, and standard deviation were used while analysing the quantitative data collection tool.Descriptive analysis technique was used in the analysis of qualitative data. In the analysis conducted in the study, it was observed that there was a difference between the reasons of students' absenteeism in terms of gender. Also, a significant difference was found according to the country they live in. According to teachers, student absenteeism originates from school, students themselves, their psychology, and parents. In addition, teachers' suggestions to reduce students' absenteeism and early school leaving were included in the interview form and evaluated in the analysis part of the study.