This issue of Veterinary Clinics: Exotic Animal Practice, guest edited by Dr. Christal Pollock, focuses on Renal Disease. This is one of three issues each year selected by the series consulting editor, Dr. Jorg Mayer. Articles in this issue include, but are not limited to: Anatomy and physiology of the avian renal system; Diseases of the avian renal system; Laboratory evaluation of renal function; Diagnostic imaging of the avian renal system; Clinical management of avian renal disease; Anatomy and physiology of the reptile renal system; Clinical management of reptile renal disease; Diagnostic imaging of the renal system in exotic companion mammals; Renal disease in amphibians; Renal disease in fish; Diseases of the reptile renal system; Diagnostic imaging of the reptile urinary system; and Renal disease in exotic companion mammals.