For this years chapter on Adrenals, we have searched the PubMed for articles on adrenal or steroidogenesis published in English between June 1, 2020 and May 31, 2021. Our search yielded more than 5,000 citations. We have examined all citations individually and selected the following collection of basic research and clinical articles. Whenever possible, we have avoided topics that have been discussed in the Yearbook 2020, unless progress in the field has been incremental. Emerging themes for this years chapter include: i) The role of neuropeptide substance P in the regulation of aldosterone secretion; ii) Kisspeptin deficiency leads to abnormal adrenal glands and excess steroid hormone secretion; iii) Urinary GC-MS steroid metabotyping in treated children with congenital adrenal hyperplasia; iv) Efficacy and safety of setmelanotide, an MC4R agonist, in individuals with severe obesity due to LEPR or POMC deficiency; v) Efficacy and safety of osilodrostat in patients with Cushings disease (LINC 3): a multicentre phase III study with a double-blind, randomized withdrawal phase; vi) First-trimester prenatal Dexamethasone treatment is associated with alterations in brain structure at adult age; and vii) Perturbed beta-cell function and lipid profile after early prenatal Dexamethasone exposure in individuals without CAH.