Poly(aniline-co-p-aminophenol) (copolymer) film was used as a sensor to determine the presence of catechol, taking advantage of the ability of the film to effectively catalyze the oxidation of catechol. The copolymer served as an electron transfer mediator between the electrode surface and catechol in the solution. The response current of the catechol sensor depended on the applied potential, pH and temperature at a given concentration of catechol. At optimum conditions, the catechol sensor displayed an excellent electrocatalytic response to the detection of catechol in a concentration range from 5 to 500μM with a detection limit of 0.8μM. The effects of selected organic compounds on the response of the catechol sensor were studied. Together, these findings show that the catechol sensor exhibits a better selectivity towards interfering species and a better operational and storage stability.