A new transamidation reaction, between an aliphatic secondary amide and an aromatic nitrile, leading to an aromatic amide and an aliphatic nitrile is described in this article. The best conditions have been established: 300 degrees C, no solvent, 2 h, 1 wt.% PPA as catalyst. Yields were found to be independent of the nature of para substituents, but strongly decrease for an ortho substituted compound. NMR studies support the mechanisms such as hydration of the nitrile, amidolysis, dehydration of the aliphatic amide leading to the aromatic amide and the aliphatic nitrile.