GaAs1-xNx solid-solution thin films of nanometric size were prepared on glass substrates by the radio-frequency sputtering technique. Atomic-force microscopy images show that the films are composed of grains with a whisker shape, whose size is practically independent of the substrate temperature. Their typical diameters range between 40 and 45 Å. The surface morphology exhibits a high density of whisker-like features that are almost normal to the substrate plane. This density increases as the substrate temperature increases, but, in essence, the nanowhisker diameter does not. Optical absorption spectra of the samples show a band-gap energy blueshift as large as 1.5 eV with respect to that of the GaAs bulk value, which was associated with strong quantum-confinement effects. Photoluminescence emission spectra in the blue range of 428–438 nm confirm the quantum-size effects in the GaAs1-xNx nanowhiskered thin films. © 2001 American Institute of Physics.