Enzyme replacement therapy has the potential to delay or reverse adverse cardiac remodeling in Anderson-Fabry disease (AFD); however, the current indications for enzyme replacement therapy rely on detecting relatively advanced features of the disease. We aimed to determine the relation between the serum N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration and cardiac abnormalities in patients with AFD. We hypothesized that it might help to detect early disease. NT-proBNP was measured under at rest conditions in 117 patients with AFD (age 48 ± 15 years, 46.2% men). All patients underwent clinical evaluation with electrocardiography and echocardiography. The median NT-proBNP concentration was 24 pmol/L (range <5 to 6,059). Of the 117 patients, 67 (57%) had elevated, age-corrected, NT-proBNP levels. In the 56 patients (48%) with normal echocardiographic findings, the NT-proBNP levels were greater than the age-predicted cutoffs in 10 of 25 patients with abnormal electrocardiographic findings and 3 of 31 patients with normal electrocardiographic findings (p <0.05). On multiple regression analysis, age, creatinine, left atrial volume index, E/Ea, and the presence of abnormal electrocardiographic findings were independently associated with log NT-proBNP (R(2) = 0.67, p <0.05). In conclusion, NT-proBNP concentrations were elevated in patients with AFD and early cardiac involvement, suggesting its measurement could assist in decisions regarding the timing of enzyme replacement therapy.