In this paper, we developed an in situ gelation method to simplify the electrospinning technique. Chromium hydroxide/polyvinyl alcohol (PVA) hybrid nanofibers were prepared by electrospinning technique and in situ gelation. Ultrathin fibers of chromium oxide with 150–200-nm diameters were obtained by high-temperature calcination of the hybrid fibers. Structural, morphological, and crystalline phase features of electrospun Cr₂O₃ nanofibers were studied by SEM, XRD, and DTA-TGA. Ethanol-sensing behavior of the nanofibers was also investigated.