A new edition of the almost legendary textbook by Schlichting completely revised by Klaus Gersten is now available. This book presents a comprehensive overview of boundary-layer theory and its application to all areas of fluid mechanics, with emphasis on the flow past bodies (e.g. aircraft aerodynamics). It contains the latest knowledge of the subject based on a thorough review of the literature over the past 15 years. Yet again, it will be an indispensable source of inexhaustible information for students of fluid mechanics and engineers alike.