Nylon 6,6 nanofiber containing an ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6), was prepared via electrospinning and used as a chemiresistor for detecting organic vapors, such as methanol, ethanol, tetrahydrofuran (THF), and acetone. The diameter of the nanofibers was varied by changing the concentration of BMIMPF6 by changing the solution viscosity and surface tension. The surface resistivity of the nanofibers decreased with increasing amounts of BMIMPF6. When the hybrid nanofibers were collected on an interdigitated electrode and exposed to solvent vapors, the resistance suddenly decreased upon exposure to all of the solvent vapors at room temperature. In contrast, the resistance dramatically increased when the organic vapors were removed. The stable cyclic test reveals that the ionic liquid containing nylon nanofiber can be used as a useful sensing material for organic vapors.