Teacher Professional Development Programs (TPD) offer an opportunity to improve education, although their results may vary considerably depending on the context and implementation. Nevertheless, they are considered relevant for addressing transformations and meeting new educational demands. In Latin America, countries such as Honduras and Nicaragua have made progress in teacher professionalization; however, important challenges remain. In this context, a pedagogical innovation project was implemented in rural schools in both countries with the objective of improving student learning through the implementation of Peer Tutoring, involving different actors. Specifically, this research focuses on the impact of this innovation in TPD as well as on the characteristics that allow its effectiveness. To address these objectives, a qualitative methodology was used, which included 19 classroom observations, designed to capture in detail the classroom interactions and didactic strategies employed by teachers. In addition, 19 individual interviews with teachers and 16 group interviews with students were conducted. The information was analyzed through thematic content analysis. The findings of the study show a significant change towards constructivist educational paradigms, which is reflected in teachers' beliefs and practices. This shift highlights the change in the teaching role, which is now seen as a mediator of learning, giving students prominence as builders of their knowledge. The belief that all students can learn if different learning paces are respected is also established. Likewise, the use and formulation of questions becomes central to promoting students' active and collaborative learning. The importance of socioemotional aspects in learning also emerged, emphasizing the creation of a bond with students to understand their interests, learning styles, and paces, and to foster a climate of trust. Key characteristics of the pedagogical innovation include flexibility and adaptability. These qualities allowed teachers to adjust the strategy to meet the specific needs of their context and their students. The innovation led to rapid and significant transformations in students, who developed greater autonomy, assumed a more active role, and improved their self-esteem and motivation to learn. This aspect is crucial for teachers'adherence to new methodologies. The strategy focused on specific content, active support, and spaces for teacher reflection, which are relevant aspects for effective TPD programs. In conclusion, the educational innovation promoted transformations in the beliefs and practices of the participating teachers, who flexibly adapted the strategy to their contexts as a result of the implementation. This is significant as it demonstrates the professionalization of the role by linking theory and practice to develop adapted strategies. Finally, a question arises about the persistence of these transformations after the project's conclusion.