Resumen: This paper presents a project on the heart carried out with children from Early Childhood Education throughout the 2017/18 school year. The main objective was to answer which scientific skills surface after an experience on the heart in Early Childhood Education to build new scientific knowledge. To do this, we designed a sequence of activities to work with the scientific practices that the students carried out with the teachers or with the lecturers. These activities integrated inquiry, modeling and argumentation practices. The sessions were recorded and transcribed for analysis by episodes. The results show us that the activities proposed allow us to work on the scientific skills that encompass the scientific practices of inquiry, modeling and argumentation in Early Childhood Education to learn about the heart, building increasingly complex models about the human body and its functioning and favouring systemic thinking. Idioma: Español DOI: 10.5565/rev/ensciencias.3213 Año: 2021 Publicado en: ENSENANZA DE LAS CIENCIAS 39, 2 (2021), 201-221 ISSN: 0212-4521 Factor impacto JCR: 1.217 (2021) Categ. JCR: EDUCATION & EDUCATIONAL RESEARCH rank: 231 / 270 = 0.856 (2021) - Q4 - T3 Factor impacto CITESCORE: 1.8 - Social Sciences (Q2)