In2O3 nanostructures such as aligned nanocolumn arrays, nanowires and nanopyramids were fabricated using a simple physical evaporation technique. Nanocolumn arrays and the nanowires were produced using an Au catalysed vapour-liquid-solid (VLS) technique and the nanopyramid structures were prepared using a non-catalytic approach. Field-emission studies revealed that the morphologies of these In2O3 nanoforms have considerable effects on the field-emission properties. Among these nanoforms, nanocolumn arrays have the lowest turn-on voltage and the highest field enhancement factor. The results indicated that the In2O 3 nanoforms could be used as cathode materials for the fabrication of devices based on field-emission properties.