One hundred and eight cases of Addison's disease, diagnosed in Danish medical departments between 1950 and 1972, were reviewed. The idiopathic type of Addison's disease predominated (66 %) while tuberculous Addisons's disease comprised only 17 % of the present series. The remaining 17 % were unclassifiable on clinical grounds. One third of the cases had symptoms less than three months prior to diagnosis and 25 % of the patients were in need of immediate treatment because of manifest or impending crisis when admitted to the hospital. Idiopathic Addison's disease was diagnosed in all age groups, predominantly in females, while patients with tuberculous Addison's disease were preferably males of higher ages. A second disease (diabetes mellitus, thyroid disorders, pernicious anaemia or gonadal insufficiency) was diagnosed in 53 % of the patients with idiopathic Addison's disease. Associated diseases were found with significantly reduced frequency in other types of Addison's disease.