Growth differentiation factor-15 (GDF-15) improves prognostication in patients with cardiovascular disorders in addition to conventional cardiac markers (N-terminal pro B-type natriuretic peptide [NT-proBNP], troponins [Tns]) and has shown prognostic value in patients with renal diseases. In patients with light chain (AL) amyloidosis, cardiac involvement is the major determinant of prognosis, and cardiac markers define prognosis, whereas biomarkers of renal involvement stratify renal risk. We explored the prognostic importance of serum level of GDF-15 in patients with AL amyloidosis in 2 independent cohorts. The prognostic value of GDF-15 level was initially evaluated in a cohort of 107 consecutive previously untreated patients with AL amyloidosis from Athens, Greece, and was then validated in a second cohort of 202 consecutive previously untreated patients from Pavia, Italy. High GDF-15 level was associated with a higher risk of early death and poor overall survival independently of NT-proBNP and high-sensitivity TnT (hsTnT) or hsTnI levels. At the 6-month landmark, reduction of GDF-15 level ≥25% was associated with improved outcome. GDF-15 level ≥4000 pg/mL was associated with a high risk of progression to dialysis, independently of renal risk defined by estimated glomerular filtration rate and proteinuria, in both cohorts; failure to reduce GDF-15 below this level was associated with increased risk at either the 3- or 6-month landmark, independently of the established renal response or progression criteria. In conclusion, GDF-15 has prognostic implications for different outcomes in patients with AL and adds prognostic information independent of that provided by cardiac and renal risk biomarkers.