Tribological characterisation of electrodeposited nickel–titania nanocomposite coatings sliding against silicon nitride in high vacuum was investigated by means of a ball on disk tribometer in a chamber at the pressure less than 5 × 10⁻³ Pa. An X-ray diffractometer, a scanning electron microscope, a Vickers microhardness tester and a surface profilometer were utilised to characterise the microstructure, morphology and mechanical properties respectively. The experimental results showed that the tribological characterisation of nanocystalline nickel in high vacuum was affected obviously by incorporating titania nanoparticles. Comparatively, the friction coefficient and wear rate of the coatings in vacuum are slightly higher than those in ambient air at room temperature.