This paper describes the fabrication of an ion-selcctive electrode in which a polymeric schiff base complex of cobalt(II) is used as the ionophore. The main advantage of the electrode is that it is mechanically stable upto 3 months. I-lie electrode shows a linear response in the range of 2.5 x 10(-5)-0.5 x 10(-1) mol dm(-3). The response time of the electrode is 30 s. The pH range at which the electrode works is 3.8 to 6.8. The electrode was found to be selective towards chloride ion in the presence of ions like Na+, Ca2+, Mn2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+, CH3COO-, NO3-, SO42-, Br- and NO2-.