SnO₂ hollow fibers with diameters ranging from 400 nm to 750 nm have been successfully fabricated by an efficient and facile approach of coaxial electrospinning. The XRD patterns demonstrate that the obtained SnO₂ samples show a pure tetragonal rutile structure. The sensor based on the SnO₂ micro/nanostructures exhibits excellent ethanol-sensing properties at a working temperature of 260 °C. It is exciting to observe that the tubular structure of the SnO₂ hollow fibers significantly improves the gas-sensing sensitivity to ethanol compared to solid SnO₂ fibers. The sensitivity of the SnO₂ hollow fiber-based sensor towards 500 ppm ethanol is about 47.14, which is about 3 times higher than that of SnO₂ fibers (14.89). It is pleasant to find that the SnO₂ hollow fibers have a rapid response time (about 1 s). The good performance can be attributed to the enhanced effective surface area. These results depict a great potential for the use of micro/nano scale SnO₂ hollow fibers for detecting ethanol.