The extraction of americium nitrate with tributyl phosphate has been investigated for aqueous solutions containing sodium nitrate and nitric acid. Americium nitrate is found in the organic phase as free molecules or ions and as the complex (Am(NO3)3. Aqueous solutions containing nitric acid introduce a competitive factor through the formation of the TBP-KNO3 complex in the solvent layer. In addition. americium nitrate is complexed in the aqueous phase by nitric acid.