Fuchs' dystrophy is an inherited disorder of unknown etiology in which the corneal endothelial cells develop morphologic and functional abnormalities. Clinically, the disease progresses slowly over a period of 20 or more years from asymptomatic cornea guttata to corneal edema with decreased vision and pain. Pathologic studies suggest abnormalities in endothelial function occurring early in life, although symptoms usually do not appear until middle age. The definitive treatment for Fuchs' dystrophy is penetrating keratoplasty. Recent findings regarding the pathophysiology of the disease have increased our understanding of it and have suggested areas for future research.