This article provides an in-depth analysis of the nature of self-assessment and its role in language learning. Self-assessment is a process of self-awareness and a realistic assessment of oneself, which helps an individual to objectively analyze his knowledge and identify areas of development. In particular, self-assessment in language learning provides an opportunity for the learner to accurately assess his/her own abilities, as well as help identify his/her strengths and weaknesses. This article presents the methodological foundations of self-assessment, its implications for language learning, and the importance of this process for teachers and learners. Through self-assessment, self-learning and efficiency increase, as well as independence and responsibility in the language learning process.