Conceptual change (CC) has become a common conception of meaningful learning, because it treats learning as an intentional, dynamic, and constructive process. Overcoming the individualistic and radical construvistic perspectives of the early 80’s, CC, nowadays, denotes a slow and gradual process that involves the creation of new ontologies and new representations, while it also signifies the ability to ﬂexibly move amongst them. This implies considerable metacognitive, epistemic and representational abilities. A central challenge for contemporary multi-dimensional CC approaches is how to simultaneously promote conceptual understanding as well as growth in reasoning, epistemic cognition and interest about science. To this end, new science education standards highlight the importance of students' participation in first-hand experiences that reflect communally recognized scientific practices. In this context reasoning in science is understood as problem-solving processes via which students arrive at justified beliefs about natural phenomena. Towards this goal many researchers emphasize the importance of model based reasoning and argumentation, as instructional practices that provide a fruitful combination of dissonance with knowledge building strategies, and also crucial understandings about the nature of science. Whereas such means have been proved successful in secondary education, there is a debate about their effectiveness among preadolescent students, due to developmental constraints. In our study, we investigated whether a learning environment of collaborative model-based problem-solving could facilitate preschool children’s conceptual change regarding the phenomenon of day and night cycle. Key features of the learning environment were: a) the use of narrating and theatrical play parts, inspired by the tale of the Little Prince, aiming to meaningfully engage preschool children, b) the construction and manipulation of play dough models by the children as means to help them make their implicit ideas overt and explain the phenomenon of day and night cycle, c) collaborative discourse and argumentative reasoning processes among students in order to examine and juxtapose each other’s models, and d) a problem-solving task that incorporated the fact, that the day and night cycle phenomenon takes place on another planet, data that could be anomalous for the geocentric intuitive conceptions. Regarding the implications of a learning environment with such characteristics to preschool children, the results show important aspects of intentional conceptual change, including reasoned change in children’s geocentric models towards heliocentric representations. We argue that these changes were the outcome of a deep engagement process, where children’s implicit ideas were gradually transformed into reasoned views. The results support the notion that intentional CC could be greatly supported and facilitated by schooling even in young ages.