Education for Sustainable Development requires improving the knowledge, attitudes and behaviors of students at all levels of education. However, this should start from the earliest stages of education, promoting an effective teaching/learning process of key concepts for sustainable development. Accordingly, the general objective of this research was to analyze the concepts of water, energy and waste in the primary education curriculum (6–12 years) in Spain. A qualitative research approach was followed, with an exploratory and descriptive design. A system of categories was established for each of the concepts under study, with the aim of classifying the references found, analyzing their integration into the different subjects, academic courses, curricular elements and levels of cognitive demand required of the students. The results of the lexicographical analysis of the content reveal that the regulations governing primary education in Spain mainly focus on the concept of energy and, to a lesser extent, on the concepts of water and waste. In addition, cognitive levels of knowledge and comprehension predominate based on the taxonomy used. The results suggest the need to develop initiatives for the educational framework that promote not only learning, but also attitudes and behaviors that contribute to achieving the Sustainable Development Goals (SDGs).