This book provides an in-depth look on Content and Language Integrated Learning (CLIL) and Early Childhood Education (ECE), two domains where major joint research is needed. By taking stock on theoretical underpinnings, it explores the ideal conditions for early additional language acquisition in preschool contexts through CLIL with a learner-centered approach grounded in developmentally appropriate practices (DEP) and an emphasis on the importance of play, cognition, holistic content adaptation and social-emotional learning. The book also offers a comprehensive view of how this methodological approach has already set a clear path on Pre-primary education internationally. Finally, it offers insights into CLIL pedagogies as related and adapted to Pre-primary education, resources and materials for very young learners and practical implementation from the classroom. By providing a solid empirical background on Pre-primary CLIL, along with appropriate methodological issues and practices, this book serves as a key resource to students, practitioners, academics as well as teacher educators and policy-makers in international contexts.