In this paper a summary of the use of the construct “mental model” in Science Education literature produced in the last ten years is presented. The diversity of understanding found on the different articles allows us to state that the concept of mental model, clearly defined and identified in Cognitive Science, is a polysemic term, in such a way that its genuine meaning is impossible to guess from reading only this literature. As a consequence, the construction of scientific knowledge in this field is quite difficult, because in this situation the conditions for it (communication of findings, comparing, discussing, evaluating, achieving consensus) are not possible, due to the lack of convergence in the meaning of the data. Other important issue can be foreseeing for Science Education itself: all the didactic consequences of applying research’s finding on mental models, as are those related to understand the students’ spontaneous thinking, its mental organisation, the uncovering of mechanisms capable to drive a conceptual change, etc., can be missed, and the teachers obstructed to apply them in their teaching activities.