This is an excellent book destined to become an indispensable reference for students, researchers, and clinicians dealing with all aspects of the pulmonary circulation. The book is divided into two sections. Section I covers the basics of the pulmonary circulation, from structure to genetics, in a thorough, readable, and up-to-date manner. It begins with a delightful and greatly appreciated historical review of the important landmarks in the evolution of our knowledge of the pulmonary circulation. A chapter on vascular structure and function follows, describing the anatomic distribution of the vascular tree down to the level of the capillary network. The authors discuss morphologic features, forces, and mediators that impact the function of the vasculature in health and disease. The importance of the interstitium and matrix in relation to the vasculature is clearly addressed. Their discussion is organized so as to couple molecular biology with known anatomic, functional, and mechanical changes and with vascular remodeling in the pulmonary circulation. The chapters on the endothelium and smooth muscle are comprehensive and clearly detailed, and provide a sound underpinning for studying the mechanisms of, and the rationale for, new therapeutic modalities in diseases of the pulmonary circulation. The authors also discuss the frequently neglected bronchial circulation and its interplay with the pulmonary circuit.