Tb3+-doped Gd2O3 (Gd2O3:Tb3+) nanofibers were prepared via a simple electrospinning technique using poly(ethylene oxide) (PEO) and rare-earth acetate tetrahydrates (Ln(CH3COO)(3)center dot 4H(2)O (Ln = Gd, Tb)) as precursors. The obtained nanofibers have an average diameter of about 80 nm and are composed of pure cubic Gd2O3 phase. A possible formation mechanism for the nanofibers is proposed on the basis of the experimental results, which reveals that PEO acts as the structure directing template during the whole electrospinning and subsequent calcination process. The luminescent properties of the nanofibers were investigated in detail. The nanofibers exhibit a favorable fluorescent property symbolized by the characteristic green emission (545 nm) resulting from the D-5(4) -> F-7(5) transition of Tb3+. Concentration quenching occurs when the Tb3+ concentration is 3 at.%, indicating that the Gd2O3: Tb3+ nanofibers have an optimum luminescent intensity under such a doping concentration.