Fabry disease is an X-linked recessive inborn error of glycosphingolipid metabolism caused by the deficient activity of the lysosomal enzyme, alpha-galactosidase A. Enzyme replacement therapy (ERT) for this disorder has been available in Europe since 2001. However, its effect on advanced renal failure remains controversial. We report the case of a patient whose decline in renal function was reduced by the administration of ERT (agalsidase-alpha). This reduction was more pronounced after doubling the dose of the enzyme. The rate of deterioration of eGFR went from 6.3 ml/min/year prior to the start of ERT (0.2 mg/kg) to 2 ml/min/year (0.4 mg/kg). To our knowledge, this is the first reported case of a patient with moderately impaired renal function treated with high doses of ERT and follow-up of 6 years. The data shown here suggest that ERT may have a very positive impact on renal function even in advanced stages. The role of proteinuria and its control seem to have a clear responsibility for this favorable outcome.