The optimization of CAL-B-promoted (Novozym 435) A/B and AA/BB type polymerizations leading to polyetheramides, from amino ethylesters or diethyl esters and diamines based on ethylene- or diethylene-glycol moieties, is disclosed herein. From these preliminary experiments it became obvious that it is of prime importance: to avoid the presence of water by carefully drying the enzyme prior to use; to eliminate ethanol from the reaction medium, by working under reduced pressure in order to drive the amidation reaction forward; to select an appropriate high boiling solvent, the best choice being diphenyl ether. Under such experimental conditions, polyetheramides were obtained in 70-80% yield with an average degree of polymerization (DPn) up to 17. (C) 2012 Elsevier Ltd. All rights reserved.