Preschool Pathways to Science (PrePS[C]) is a science and math program for pre-K children that has been developed by a team of developmental psychologists in full collaboration with preschool directors, teachers and other staff. The PrePS[C] approach is rooted in domain-specific theories of development, theories that assume that different areas of knowledge are organized into separate mental structures as opposed to domain-general ones like concrete operations. Features of this theoretical stance are outlined, and their implications for educational practice are illustrated using examples from classroom practice. Specific attention is paid to the importance of science process skills, the need to connect experiences using a central concept, and the roles of math, communication, and literacy in a science-based learning approach. Finally, the critical interdependence of basic research and classroom practice is discussed.