Inhalation aerosols continue to be the basis for successful lung therapy for a variety of diseases. Since the turn of the millennium, many new products have been approved. Arguably the most substantial have been the first approved inhaled drugs and drug combinations for the treatment of chronic obstructive pulmonary disease (COPD). More recently, the development of drugs to treat pulmonary infection and diabetes has continued the translation of drug therapy to aerosol technology. With this background, it is evident that technological advancements and therapeutic strategies have evolved since the first two editions of this book were published. The original focus on asthma as the most significant target of inhaled therapy has broadened to include numerous local and systemic diseases. And the range of technology forming the basis for novel inhaler design has expanded significantly. In this text, rather than simply expand and update the original two editions, we decided to address the close integration of technology with its application. An introductory section (Part I) on the fundamental science acts as a transition from past volumes to the present text by presenting briefly the general considerations that apply to physical chemistry, device technology, aerosol physics, lung deposition, clearance, physiology, and pharmacology.Part II represents a new approach in which a disease and therapeutic agent focus is employed to illustrate the application of a technology. It is evident from the number of chapters in this section (13) that the opportunities for the application of aerosol drug delivery have increased dramatically in recent years. Finally, an integrated strategies section (Part III) draws the major points from the applications regarding disease targets and drug products in the form of generalizations that may be valuable to readers. In modifying the approach to the structure of the book, we are aligning with the translational imperative that has emerged in the last decade. In addition, this third edition is aligned with the latest scientific initiatives on precision medicine that has been gaining much attention recently. This approach encompasses precision pulmonary medicine. The ability to extract knowledge rapidly and effectively from study data and apply it in a therapeutically relevant manner is considered an urgent demand of the scientific and clinical research community. In presenting the content as described in this preface, we hope that relevance to development and clinical evaluation can be established.