Substantial further advances in our understanding of adrenal development, steroid biosynthesis and adrenocortical disorders necessitate another look at this small but complex organ. In this volume, leaders in the fields of adrenal development, biochemistry and genetics review the most recent findings from bench and bedside research. New aspects of adrenal development and zonation and the novel ‘backdoor’ pathway to androgen synthesis are discussed. P450 oxidoreductase deficiency (a newly described form of congenital adrenal hyperplasia) and long-term outcome of prenatal treatment of 21-hydroxylase deficiency are examined. An update on ACTH resistance and adrenal Cushing’s syndrome is provided. Finally, the role of adrenal steroidogenesis in arterial hypertension and fetal programming of adrenal androgen excess as a possible explanation for polycystic ovary syndrome in later life are analyzed. This book will be of great interest to pediatric, adult and reproductive endocrinologists, clinical geneticists, developmental biologists and basic scientists working in the fields of endocrinology and steroidogenesis.