Fabry disease is an X-linked, hereditary, lysosomal storage disease caused by deficiency of the enzyme alpha-galactosidase A, which results in the accumulation of the neutral glycosphingolipid globotriaosylceramide (Gb3) in the walls of small blood vessels, nerves, dorsal root ganglia, renal glomerular and tubular epithelial cells, and cardiomyocytes. It is a complex, multisystem disorder that is characterized clinically by chronic pain and acroparesthesia, gastrointestinal disturbances, characteristic skin lesions (angiokeratomata), progressive renal impairment, cardiomyopathy, and stroke. Enzyme replacement therapy (ERT) with intravenous infusions of recombinant human alpha-galactosidase A consistently decreases Gb3 levels in plasma and clears lysosomal inclusions from vascular endothelial cells. The effects of ERT on other tissues are not as obvious, suggesting that treatment must be initiated early in the course of the disease to be optimally effective or that some complications of the disease are not responsive to enzymes delivered intravenously.