Bismuth oxide films and nanostructures were deposited using reactive plasma assisted thermal evaporation. The growth temperature varied in the range of 30-500 degrees C in order to obtain the single phase Bi2O3. The as-deposited Bi2O3 structures were characterized for their structural, surface morphological and optical properties using X-ray diffraction (XRD), scanning electron microscopy, and optical absorption measurements, respectively. The XRD analyses demonstrated the formation of Bi2O3 films amorphous phases at deposition temperatures below 200 degrees C. Meanwhile the crystalline phase's (beta-Bi2O3 with delta-Bi2O3 or delta-Bi2O3) bismuth oxide nanostructures were formed at higher grown temperatures. The nanostructures were approximately 100-500 nm of length with the diameter of 50-100 nm. The optical band gap of Bi2O3 films and nanostructures varied in the range of 2.75-3.05 eV. (C) 2015 Elsevier B.V. All rights reserved.