Although primary adrenal failure is considered a rare condition, recent epidemiological studies indicate a rising incidence of the disease owing to the increase of autoimmune disorders. Addison's disease may be a life-threatening condition and the occurrence of pregnancy has been considered as a dangerous event. Nowadays, adrenal insufficiency during pregnancy is associated with high incidence of serious fetal and maternal complications, as fetal death in utero and post-partum adrenal crises, only if the disorder is not recognized and adequately treated. In this article pathophysiological aspects, clinical features and guidelines of management of pregnancy in Addison's disease are reviewed.