The fracture behavior of a brittle polymer, polymethyl methacrylate (PMMA) resin, under impact tensile loading was studied using single-edge-cracked specimens. The dynamic load and displacement were measured with a Piezo sensor and a high-speed extensometer, respectively. The load and displacement diagram, i.e., the external work U_ex applied to the specimen was used to determine the elastic energy E_e and non-elastic energy E_n due to viscoelastic and plastic deformation, and the fracture energy E_f for creating new fracture surface A_s. The energy-release rate was then estimated using G_f=E_f/A_s. The values of E_e, E_n, E_f and G_f were correlated with the fracture loads, and compared with the ones earlier determined for the static loading conditions.