An yttrium (III) cation selective electrode based on kryptofix-22DD (1,10-didecyl-1,10-diaza-18-crown-6) incorporated into a polyvinylchloride (PVC) membrane has been developed. The optimized membrane incorporating dibutylphtalate (DBP) as plasticizer, kryptofix-22DD and palmitic acid as a new component in a highly selective and sensitive coated wire electrode (CWE) for yttrium (III) cation was directly coated on the surface of a platinum wire electrode. The selective electrode showed more effective performance than other yttrium (III) cation PVC based sensors. The electrode exhibits a Nernstian slope (18.89 +/- 0.43 mv.decade(-1)) in a wide linear concentration range of 1.0 x 10(8) -1.0 x 10 (1) M. The detection limit of electrode is 2.15 x 10 (9) M. The effects of the pH and possible interfering ions were investigated and the optimized conditions for electrode were evaluated. The electrode was applied as an indicator electrode for potentiometric titration of yttrium (III) cation in solutions. Determination of fluoride ion in tap water, mouthwash and toothpaste gave results that compare favorably with those obtained by the fluoride ion selective electrode. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3582316] All rights reserved.