This textbook is a go- to book for aspirants of Pediatric Pulmonology and Critical Care, and a handbook for quick reference for practicing pediatric pulmonologists. The fourth edition further builds on the USP of this book- easy to understand, systematic and schematic approach to even complex topics of core pulmonology. Recent updates, comprehensive tables and flow charts make this new edition as pleasurable to read as its predecessors. My hearty congratulations to the authors on their continued strife towards excellence in teaching, as both have devoted their careers in advancement of the field and training of budding pediatric pulmonologists and intensivists.