The use of nanomaterials in asphalt binders has become a very promising approach to improve the performance of pavements under growing traffic and environmental load. This research focuses on the influence of zinc oxide (ZnO) nanoparticles on physical and rheological properties of asphalt binder. ZnO was added in dosages of 1%, 3%, 5% and 7% by binder weight in a high shear mixing process. The modified and control binders were tested for their physical properties (penetration, softening point, ductility, flash point and viscosity), Dynamic Shear Rheometer (DSR) tests for rutting and fatigue performance and Bending Beam Rheometer (BBR) testing for low temperature behaviour. The results showed that the addition of ZnO nanoparticles reduced penetration and increased softening point, flash point and viscosity, which indicated the improvement of stiffness and thermal stability. Ductility was not affected, which confirmed that flexibility was maintained. Rheological analysis revealed that rutting resistance was significantly improved and a 76.7% reduction in the fatigue factor was observed in intermediate temperatures, whereas BBR results revealed acceptable low-temperature performance. The Performance Grade (PG) of the binder was improved up to two grades in higher contents of ZnO without exceeding limits for workability or thermal cracking. These results show that ZnO nanoparticle is an efficient asphalt modifier that enhances thermal, mechanical and rheological properties and thus can be used in high performance pavements applications with a wide range of temperature.