Nanoscale structures of aluminium oxide (Al₂O₃) and zinc oxide (ZnO) multilayers (nanolaminates) were prepared by atomic layer deposition (ALD) on silicon substrates at 120 °C. The focus of this work was to study the effects of bilayer period on mechanical properties and the effect of the ratio between the thicknesses of each material with bilayer period kept constant. We found that reduction of bilayer period led to an increase in hardness of the nanolaminates, which was explained by the Hall–Petch effect. The influence on hardness of the thickness ratio between Al₂O₃ and ZnO, where it increased by 50% for Al₂O₃/ZnO = 1:24 with bilayer period = 25 nm was observed. Progressive scratch tests revealed that the highest critical load for delamination and the highest toughness was observed for samples with Al₂O₃/ZnO = 24:1 with bilayer period = 25 nm.