The use of the recently synthesized pyridine-containing thia-aza macrocycle 2,8-dithia-5-aza-2,6-pyridinophane as an anion receptor in a PVC-membrane based ionselective electrode was studied. The sensor showed selectivity towards perchlorate anions with a linear working range of 2.1×10-7 to 1.3×10-1 M. The characteristic response of the membrane-based perchlorate-selective electrode and the selectivity coefficients towards common diverse ions using dibuthyl phthalate (DBP) as plasticizer were also determined. The proposed electrode showed a near-Nernstian slope with detection limit of 2.0×10-7 M (20 ppb) and was used successfully to determine the perchlorate concentration in drinking water.