The objective was to determine the effect of an educational intervention on the level of oral health knowledge in primary school teachers in the district of Huayrapata - Puno, Peru.  Methodology: The research approach was mixed, the pre-experimental, longitudinal, and prospective designs. The sample consisted of 32 teachers from eight educational institutions selected as non-probabilistic for convenience considering the sample selection criteria. The study was carried out in three periods. First, a questionnaire of 18 questions was applied to teachers to determine the level of knowledge about preventive measures, main oral diseases, and dental development. Subsequently, the educational intervention was carried out, which consisted of didactic training with images and videos for teachers. Finally, the teachers were evaluated with the same 18-question questionnaire. The levels of knowledg...