Self-assessment is a process by which a learner collects information about him, and reflects on his/her learning. Self-assessment of students includes reflective activities in which students are encouraged to consider the strengths and weaknesses of their work. Students can improve their self-regulation skills through self-assessment. The purpose of this study is to reflect pupils' perceptions about their self-assessment in learning in Kosovo pupils, taking in consideration that pupils' self-esteem is new and has not been applied until now. In the study, will be involved 725 students from 12 to 18 years old, four hundred pupils from lower secondary school and three hundred and twenty-five upper secondary school students. The research is conducted directly with the students using the quantitative research method, questioning the participants through the questionnaire. Participants' response analysis clearly shows that self-assessment helped to develop awareness and metacognitive behavior among students. Most respondents in questionnaires have found useful self-assessment as a learning tool. The results show that both students' and teachers' perceptions consider that pupils' self-assessment in the classroom is present, but not even at a very satisfying level. To students, the result is significant at p < 0.05 (p< 0.00001) and to teachers the result is not significant (p = 0.969701).