: After reviewing briefly the influence of the incorporation of vanadium in the uranium matrix (for contents between 0.0 and 0.5), we will examine the effect of major impurities, mainly carbon, nickel and iron, on the properties of the uranium-0.2% vanadium alloys. Tensile tests at both ambient and elevated temperatures were conducted, together with some compression tests of cylinders in isothermal conditions, under primary vacuum. The results of these tests will be discussed in connection with metallurgical observations : viz, the growth of the grain boundaries and the recrystallization phenomena will be briefly examined and compared with the mechanical results.