A common reason for referring patients to hepatologists is persistently abnormal serum transaminase levels with vague constitutional symptoms. In the United Kingdom, these abnormalities are most often caused by a fatty liver either related to obesity or alcohol abuse; they are less commonly caused by chronic liver disease, particularly chronic viral hepatitis, autoimmune hepatitis, or chronic biliary disease. Endocrine disease is rarely a cause of these abnormalities, although hypothyroidism and hyperthyroidism are well-recognized causes. Addison's disease has been only reported once in the literature by R. G. Olsson as a cause of increased transaminase levels associated with constitutional symptoms; it is not mentioned in textbooks on hepatology. Three patients with Addison's disease are reported here, all of whom had increased serum transaminase levels for more than 6 months before the recognition of the hypoadrenalism with resolution to normal after steroid replacement. Hepatologists should consider subclinical Addison's disease as a cause of persistently increased transaminase levels with constitutional symptoms in the absence of evidence for fatty liver as well as viral and autoimmune markers.