Corticotropin-releasing hormone (CRH) and related peptides (urocortins, sauvagine, urotensin) play a central role in the co-ordination of autonomic, behavioural, cardiovascular, immune and endocrine responses to stressful stimuli. Their actions are mediated through activation of two types of G-protein-coupled receptors encoded by separate genes. In this review we focus on the diverse structural and functional characteristics of the family of CRH-like peptides and their receptors.