Istraživanje je provedeno s ciljem utvrđivanja navika samovrednovanja postignuća kod učenika srednje škole i uočavanja razlika učenika u navikama samovrednovanja s obzirom na spol i školski uspjeh. Istraživanje se provelo školske godine 2018./2019. na uzorku od 61 učenika trećih razreda jedne osječke gimnazije. Provedena je pisana provjera znanja i anketa. U pisanoj provjeri znanja usporedio se očekivan i ostvaren broj bodova radi objektivne prosudbe učeničke sposobnosti samoprocjene postignuća. Subjektivan doživljaj sposobnosti točne samoprocjene postignuća kao i ostale navike samovrednovanja utvrđene su anketom. Provedenim istraživanjem je utvrđen nesklad između ostvarenog i očekivanog uspjeha, kao i nesklad između percipirane i stvarne sposobnosti točne samoprocjene vlastitog uspjeha. Učenici precjenjuju svoj uspjeh i vlastite mogućosti samoprocjene znanja. Također je utvrđeno da postoji svijest o važnosti samovredovanja, ali im nedostaju navike i iskustvo u toj vještini.The aim of the research is to determine the self-assessment habits of high school students and to determine whether the students differ in self-assessment habits with regard to sex and school success. The research was performed during the 2018/2019 school year on the sample of 61 third-grade high school students from one gymnasium in Osijek. A written exam and a questionnaire were conducted. In the exam, the expected and achieved scores were compared in order to objectively assess the student\u27s self-assessment of school achievement. Subjective experience of the ability to accurately self-assess achievement as well as other habits of self-assessment were determined by the questionnaire. The research identified a discrepancy between achieved and expected success, as well as a discrepancy between the perceived and actual ability to accurately self-assess one\u27s own success. Students overestimate their success and their own ability to self-assess knowledge. It was also found that there was an awareness of the importance of self-assessment, but students lack habits and experience in this skill