The potentiometric response of PVC/dicyclohexyl-18-crown-6 membrane ion sensors to nonionic alcohols has been measured. The ion sensors are potentiometrically sensitive to lipophilic alcohols such as 1-hexanol, 1-heptanol, 1-octanol, and 1-nonanol at the millimolar level or lower, whereas low-lipophilicity alcohols, including methanol, ethanol, ethylene glycol, diethylene glycol, and 1,3-propanediol, have no influence on the sensor response. The results are discussed in terms of specific adsorption and penetration of the alcohols to the PVC/crown ether membrane.