A vanadium-based alloy with 5%(wt) Cr and 5%(wt) Ti (V-5Cr-5Ti) is being considered as a candidate structural material for a fusion energy system. Besides retaining its good strength and ductility at both ambient and elevated temperatures, vanadium-based alloys possess some unique neutronic properties as compared to austenitic and ferritic steels. Low neutron activation in the short-term, and especially in intermediate and long terms, and low biological hazard potential are particularly attractive properties of vanadium alloys. However, the alloy was found to be brittle at room temperature (RT) and experienced mixed intergranular and cleavage fracture when annealed at 1,125 C for 1 h and furnace cooled. It has been known that S segregation to grain boundaries can induce intergranular fracture in iron and nickel-based alloys. This study was designed to investigate systematically the effect of grain boundary chemistry on the fracture properties of the alloy.