Tensile properties at 298 and 77 K of the electron-beam-welded joints of low neutron activation vanadium-binary alloys were evaluated. (1) Yield and tensile strengths of the welded specimens increased with an increase of carbon of up to 1.6%, boron of up to 5.0% and chromium of up to 9.3% by weight. (2) All the materials were embrittled by the welding, though the order of embrittlement depended on the additive and its content. The order of embrittlement was the least for vanadium-boron (V-B) alloys and the most for vanadium-chromium (V-Cr) alloys. (3) The location of fracture in the tensile specimens was in the weld metal for V-C and V-Cr alloys and the heat-affected zone (HAZ) for V-B alloys. Fracture mode depended on the additive and temperature. Most of the alloys at 298 K and V-B alloys at 77 K showed the ductile fracture, while V-C and V-Cr at 77 K showed the cleavage fracture.