A convenient FeCl3-catalyzed synthesis of N-sulfonylimines via the condensation of aldehydes with N-sulfonylamides in mild and neutral conditions (in ethanol at room temperature) is reported. This procedure constitutes the first iron-catalyzed synthesis of N-sulfonylimines and is adapted to the condensation of both aromatic and aliphatic aldehydes. (C) 2009 Elsevier Ltd. All rights reserved.