As the preparation of interpolymer type ion-exchange membranes involves the use of hazardous chemicals like chlorosulfonic acid and chloromethyl ether, it was envisaged to prepare heterogeneous membranes through a simple technique involving casting of a solution containing a binder and a polyelectrolyte. This paper reports the studies conducted in the preparation of heterogeneous cation-exchange membranes using polyvinyl chloride (PVC) as binder and cation-exchange resin powder as polyelectrolyte by the solution casting method. The effect of the particle size and loading of resin on the properties of the: membranes such as dimensional stability, bursting strength, ion-exchange capacity, electrical resistance, transport number etc. have been studied. It has been found that with respect to dimensional stability the properties of the heterogeneous cation-exchange membranes prepared by using resin of suitable particle size and loading, are almost equally good or even better than interpolymer cation-exchange membranes and hence heterogeneous cation-exchange membranes may replace the interpolymer membranes in some of the electrodialysis (E.D.) applications. (C) 2000 Elsevier Science B.V. All rights reserved.