The adhesion of Pt thin films to NiO substrates has been studied using the continuous microscratch technique. Films of Pt ranging from 65 to 1080 nm in thickness were sputter deposited onto single crystals of NiO. Continuous microscratch experiments were performed by driving a conical diamond indenter, with a nominal radius of 5 μm, simultaneously into and across the film until a load drop was observed indicating that the film had delaminated. The practical work of adhesion was calculated using a theoretical model developed for metal-ceramic systems. The practical work of adhesion increases from 0.03 to 4.7 J/m2 as the film thickness increases from 65 to 1080 nm. The practical work of adhesion includes the true work of adhesion — the energy to produce two new surfaces — and terms involving the plastic deformation of the film and substrate. Extrapolation of the practical work of adhesion versus film thickness data to zero thickness yields a first order estimate of the true work of adhesion. The true work of adhesion for the as-sputtered Pt/NiO system is determined to be 0.025 J/m2, a value of the same order as the Van der Waal’s energy.