When a thin film is deposited by physical vapour deposition, with the vapour flux arriving at an oblique angle from the substrate normal, and under conditions of sufficiently limited adatom mobility to create a columnar microstructure, the resulting structure is somewhat porous and grows at an angle inclined toward the vapour source. This technique called glancing angle deposition was used in this work to grow nanocrystalline cuprous oxide thin films by annealing in air of copper films deposited firstly by this method onto glass substrates. The films were characterized for their structural, surface morphological, compositional; electrical and optical properties by using X-ray diffraction (XRD), scanning electron microscopy (SEM), electrical resistivity and optical (transmittance and reflectance) measurement techniques. It was found that the above properties were strongly dependent on the obliquely angle deposition. The nanocrystallite size in these films was varied by varying the obliquely angle deposition. Optical studies show a direct allowed transition around in the range 1.5–1.85 eV for the annealed films. An enhancement in the oxidation process was observed for high obliquely angles deposition.