This first edition of Principles and Practice of Pediatric Endocrinology brings together 30 authors from 4 countries to present an update on the molecular basis of endocrine disorders in infants, children and adolescents as well as the diagnosis and treatment of these conditions. It is intended for the use of practitioners, fellows and clinical and “bench-top” researchers in this field, and presents advances in each of 12 areas of the normal and abnormal endocrine state. The work is a tribute to all those past and present whose research and clinical efforts resulted in the rapidly increasing accumulation of knowledge in this field, and includes comprehensive, practical clinical presentations in the form of an Atlas following each chapter after the comprehensive introductory chapter by Drs. Root and Rogol. This publication owes a great debt to Lawson Wilkins, a Baltimore pediatrician who first formally established the separate discipline of pediatric endocrinology, to Edwards Park, Fuller Albright, Bob Blizzard, Claude Migeon, Harold and Helen Harrison, James Tanner and to so many others: giants upon whose shoulders pediatric endocrinologists stand. Disorders of growth and pubertal development are the cornerstones of pediatrics as they are present in many children with chronic illness as well as in children whose growth and pubertal development are influenced by genetics and family history. These may have identifiable causes in pituitary, thyroid, adrenal or gonadal function, and examples are well represented in this book. Obesity and diabetes (types I and 2) are, likewise, diseases of childhood that are becoming increasingly and significantly prevalent and are included in this work. Disorders of calcium/phosphorus (especially the often forgotten but not gone Vitamin D deficiency rickets) and water metabolism are presented, and errors of sexual differentiation (an increasingly controversial issue) are highlighted. It is the hope of the editors that this work will assist the practitioner and researcher in this field in his or her efforts to diagnose, treat and establish the etiology of endocrine disorders in infants, children and adolescents.