Self-assessment is one of the most usual activities in classroom from all different educational levels. However a high percentage of teachers report not knowing how self-assessment influence students' learning or how to implement it successfully in their classrooms. In this article two different lines of research concerning self-assessment will be analysed (self-regulation and formative assessment) along with a new conceptualization of what self-assessment is. Later the relationship between self-assessment and the use of learning strategies by the students will be examined explaining how this skill can be acquired. In the last sections it will be analysed how the use of different pedagogic strategies can enhance a successful implementation of self-assessment in classrooms.