LaOBr:Yb3+/Er3+ nanofibers were synthesized for the first time by calcinating electrospun PVP/[La(NO3)(3) + Er(NO3)(3) + Yb (NO3)(3) + NH4Br] composites. The morphology and properties of the final products were investigated in detail using scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), X-ray diffractometry (XRD) and fluorescence spectroscopy. The results indicate that LaOBr:Yb3+/Er3+ nanofibers are tetragonal in structure with a space group of P4/nmm. The diameter of LaOBr:Yb3+/Er3+ nanofibers is similar to 147 nm. Under the excitation of a 980-nm diode laser, LaOBr:Yb3+/Er3+ nanofibers emit strong green and red up-conversion emission centering at 519, 541 and 667 nm, ascribed to the H-2(11/2), S-4(3/2) -> I-4(15/2) and F-4(9/2) -> I-4(15/2) energy-level transitions of Er3+ ions, respectively. The up-conversion luminescent mechanism of LaOBr:Yb3+/Er3+ nanofibers is advanced. Moreover, near-infrared emission of LaOBr:Yb3+/Er3+ nanofibers is obtained under the excitation of a 532-nm laser. The formation mechanism of LaOBr:Yb3+/Er3+ nanofibers is proposed. LaOBr:Yb3+/Er3+ nanofibers could be important up-conversion luminescent materials. Copyright (C) 2014 John Wiley & Sons, Ltd.