A novel voltammetric sensor based on ZnO-Al2O3 ceramic nanofibers and gold nanoparticles (AuNPs) was used for simultaneous determination of catechol and hydroquinone. The sensor was fabricated using ZnO-Al2O3 ceramic nanofibers for modification of glassy carbon electrode (GCE). Ceramic nanofihers were electrodeposited onto the mixture of graphene oxide (GO) and chitosan (chit) simultaneously with gold nanoparticle electrodeposition. The morphology and the structure of ceramic nanofibers were characterized by Field Emission Scanning Electron Microscopy (FESEM), energy-dispersive spectroscopy (EDS) and Fourier transform infrared (FTIR) spectroscopy. The porous structures can be used for the simultaneous detection of isomers due to their satisfied results in concurrent analytes determination; then the porosity of ZnO-Al2O3 ceramic nanofibers was determined using Brunauer-Emmett-Teller (BET) test. The sensor has been applied for simultaneous determination of catechol and hydroquinone which indicated good results. The limit of detection and linear ranges are obtained 3.1 and 0.5 to 40 mu M for catechol respectively. For hydroquinone, there are two linear ranges, 0.13 to 1 mu M and 1.5 to 56.6 mu M, and two limits of detection, 0.19 and 15.0 mu M respectively. For catechol, the amounts of alpha and k(s) were 0.43 and 1.12 s(-1), respectively and for catechol, they were 0.35 and 0.41 s(-1), respectively.