The interaction of radiation-induced defects with deuterium atoms at room tenperature was studied for commercial vanadium, V-H and V-D alloys. During a 700 keV D+ bombardment the accumulation of D in the irradiated area was measured by means of NRA using the reaction D(d,p)T. It was shown that in the irradiated area of the V-D alloys (0.01–0.1 at .% D) the D concentration depends on both the fluence and the alloy composition. As the fluence is increased, the accumulated amount saturates. The saturation level depends on the D concentration and is 3 to 6 times as high as the D concentration in the bulk. The D segregation is due to the formation of immobile or low-mobile “D atom — radiation defect” conplexes. At the same time free D atoms are almost immediately redistributed in the bulk of the sample. A complex deuterium-protium segregation in V-D and V-H alloys under D+ bombardment was studied too. The accumulation of implanted deuterium in the irradiation-damaged area was examined for alloys with a high (0.6–2.65 at .% H) content of 1H hydrogen isotope. It is shown that the implant accumulation level is indepedent of the bombardment dose but is determined by the content of “free” protium in the alloys: the higher the protium concentration, the lower the accumulation level.