First, several disc-type test samples weakened by a central bean-shaped slit with two U-shaped ends, called U-notched Brazilian disc (UNBD) specimens, made of commercial graphite, were prepared. Four notch tip radii were considered in the tests. Then, a monotonic compressive load was diametrally applied to each sample along the slit, resulting in pure mode I loading. After sudden fracture, the fracture loads were recorded and converted into the corresponding values of the notch fracture toughness (NFT) K Iq,c . The main advantage of the UNBD specimen is that the NTF test can be easily conducted without using complicated fixtures. The well-established brittle fracture model, namely the strain energy density (SED) over a specified control volume, which embraces the notch edge, was employed to estimate the fracture loads theoretically. A good agreement was found between experimental and theoretical results. Under Mode I loading, the SED and the NFT are linked by a simple relationship providing a powerful tool for the fracture assessment of different specimens and structural components weakened by notches.