Introduction. In the current educational context, learning basic mathematics and natural sciences is one of the processes that present some difficulties, especially in the early years of education. This is since the development of logical, mathematical, and scientific thinking is approached conceptually, hindering students' ability to connect theory with their daily lives. Objective. To design a proposal for integrating basic mathematics and natural sciences through play-based learning experiences in early childhood education, to be applied with first, second, and third-grade students at the Don Bosco Catholic School. Methodology. An exploratory, practical, field, and longitudinal study with a quantitative design and a quasi-experimental approach, based on the analytical-synthetic method. Initial and subsequent observations were conducted following an intervention with a sample of 67 first, second, and third-grade students. Results. The results show a significant improvement in the effectiveness of the methodology applied to integrate Basic Mathematics into Natural Sciences. During the initial observation, most students demonstrated a low level of effectiveness in this integration; however, after the implementation of the proposal, this percentage increased, demonstrating its effectiveness. Conclusion. The implementation of a proposal for integrating Basic Mathematics and Natural Sciences through play-based learning proved to be an effective strategy for improving early learning in first, second, and third-grade students at the Don Bosco Catholic School. The use of play-based learning fosters conceptual understanding, motivation, scientific thinking, and the practical application of knowledge, generating meaningful, dynamic, and contextualized learning for children. General Area of Study: Education. Specific area of study: Basic General Education. Type of study: Original article.