The general aim of this study was to analyse how the History of Mathematics is being used in the classroom as a methodological resource in the teaching and learning of mathematics by teachers in the municipality of Baia Formosa - RN. To this end, we chose as a basis some theorists such as Miguel and Miorim (2011), D'Ambrosio (1999), Mendes (1997), Miguel (1997), among others. The research was designed as a case study, of a qualitative and exploratory nature. In order to achieve the proposed objective, we drew up a questionnaire for data collection, which was applied to four maths teachers from primary and secondary schools in the municipality of Baia Formosa/RN. The aim was to contribute to the teachers' practice by reflecting on and looking for methods that could help and enrich the students' teaching-learning process. The results of the research showed that the use of the History of Mathematics is restricted to what is presented in textbooks, the main reason being the lack of knowledge about the History of Mathematics, caused by the lack of a History of Mathematics subject in academic courses and continuing training.