The irradiation hardening of the Eurofer97 steel following 590 MeV proton irradiations was determined at three different irradiation temperatures, 50 °C, 250 °C and 350 °C, and various doses up to about 1.3 displacement per atom. The dose and temperature dependence of the irradiation hardening was characterized by a linear relationship between the irradiation hardening and the square root of the dose as: delta_yield_stress=k(T)dpa^1/2. Mini pre-cracked bend bar (1x1x16 mm3) were also tested in the lower ductile to brittle transition region before and after irradiation at 300 °C and 0.5 dpa. The effective fracture toughness-temperature curves, Ke(T), were indexed on an absolute temperature scale at To for Ke=100 MPa m1/2 for both the unirradiated and irradiated condition. The irradiation-induced temperature shift delta_To of the Ke(T) curves yielded a coefficient Co, defined as Co=delta_To /delta_yield_stress, of about 0.53. For these low doses, helium effects could not be identified on the fracture properties.