Understanding the embryological morphological and molecular development of the adrenal gland is a precondition for the pathophysiological understanding of congenital adrenal deficiencies. Knowledge about the embryological development also allows to appreciate the location of adrenal ectopic tissue and of familial syndromes of congenital adrenal hypoplasia or neoplasia induced by mutations in transcription factors responsible for the regular development of the adrenal gland. The development of the human fetal adrenal is complex and under control of several hormones, growth factors, and transcription factors, which are critical for the early development of the hypothalamic-pituitary adrenal axis. There have been great strides in deciphering these complicated molecular aspects directing the adrenogonadal primordium into the adrenal cortex, kidney, or bipotential gonad. The adrenal gland continues significant remodeling during neonatal and pubertal periods. The definitive adult structure of the cortex is not achieved until near puberty.