The purpose of this research was to study the effect of the changes in the strategies to stimulate self-concept used by teachers, that received training, in the academic self-concept of its students. A quasi-experimental design with pre- and post-application measures was used. A total of 36 secondary school teachers and 814 students participated. The program consisted of four months of workshop sessions and accompaniment in the classroom. It was found that changes in the teaching strategies mediated the effect of the intervention on students’ self-concept. In addition, the change in the students’ type of self-concept depended on the change in the teachers’ specific strategies. In conclusion, the training program designed for stimulating academic self-concept was effective in promoting strategies in teachers that increased student’s self-concept. Thus, it can be concluded that the intervention is an approachable methodology to support the development of self-concept, potentially impacting students’ academic success. The findings contribute to the design of future interventions in school contexts for the improvement of students’ self-concept.