The synthesis of a soluble poly(ether ketone) (PEK) precursor via a ketimine route is described. The synthesis is realized by using a halogenophenol monomer, i.e. N-(4-fluoro-4'-hydroxydiphenylmethylene) imine. First we describe the synthesis of the monomer and its characterization by infra-red and C-13 nuclear magnetic resonance spectroscopies. Subsequently, the polymerization of the monomer is reported and the factors influencing the polymerization reaction are considered. The ketimine PEK prepolymer is soluble in common organic solvents. The rate of the ketimine PEK condensation is decreased compared with that of the equivalent ketimine poly(ether ether ketone) condensation due to the deactivation of the reactive intermediate (Meisenheimer's complex). The poly(ether ketimine) can be readily hydrolysed to the poly(ether ketone). Copyright (C) 1996 Elsevier Science Ltd.