In today’s knowledge-based societies, understanding basic scientific concepts and the capacity to structure and solve scientific questions is more critical than ever. Accordingly, in this paper we test an innovative methodology for teaching science and environment in public primary schools where traditional (teacher centred) teaching was replaced with student centred activities using LEGO kits. We document positive and significant improvements of 0.18 standard deviations in standardised test scores. Such positive results are mainly concentrated within boys that were located above the median of baseline academic performance.