Objective: We developed clinical practice guidelines for congenital adrenal hyperplasia (CAH). Participants: The Task Force included a chair, selected by The Endocrine Society Clinical Guidelines Subcommittee (CGS), ten additional clinicians experienced in treating CAH, a methodologist, and a medical writer. Additional experts were also consulted. The authors received no corporate funding or remuneration. Consensus Process: Consensus was guided by systematic reviews of evidence and discussions. The guidelines were reviewed and approved sequentially by The Endocrine Society's CGS and Clinical Affairs Core Committee, members responding to a webposting, and The Endocrine Society Council. At each stage, the Task Force incorporated changes in response to written comments. Conclusions: We recommend universal newborn screening for severe steroid 21-hydroxylase deficiency followed by confirmatory tests. We recommend that prenatal treatment of CAH continue to be regardedas experimental. The diagnosis rests on clinical and hormonal data; genotyping is reserved for equivocal cases and genetic counseling. Glucocorticoid dosage should be minimized to avoid iatrogenic Cushing's syndrome. Mineralocorticoids and, in infants, supplemental sodium are recommended in classic CAH patients. We recommend against the routine use of experimental therapies to promote growth and delay puberty; we suggest patients avoid adrenalectomy. Surgical guidelines emphasize early single-stage genital repair for severely virilized girls, performed by experienced surgeons. Clinicians should consider patients' quality of life, consulting mental health professionals as appropriate. At the transition to adulthood, we recommend monitoring for potential complications of CAH. Finally, we recommend judicious use of medication during pregnancy and in symptomatic patients with nonclassic CAH. Copyright © 2010 by The Endocrine Society.