Polycrystalline diamond compacts (PDC) cutters are widely used in oil and gas well drilling and a different format of the same material is also used in high speed turning. During the cutting process these tools experience very high temperatures and impact loads which lead to their sudden fracture. In this work the mechanical and fracture properties of two different grades of PCD test specimens, i.e. the Young’s modulus and fracture toughness, are measured under a range of test conditions such as temperature and loading rate, which correspond to the actual drilling conditions. The fracture is found to propagate in a highly dynamic manner, where the results show the examined properties of PCD specimens to vary with the loading rate and temperature. The study performed leads to a greater understanding of PCD behaviour, and aims to provide guidance for improved material design.