Mn2 - x Cox V Ga (x = 0.5, 0.75 and 1) compounds were synthesized by arc melting to investigate the effect of cobalt substitution on the magnetic and transport properties of the half-metallic ferrimagnetic compound Mn2VGa. The lattice parameter value decreases with the substitution of Co. The compounds Mn1.25Co0.75VGa and MnCoVGa showed a substantial reduction in magnetic moment due to anti-parallel alignment of the Mn moment with Co and V moments and the Mz value for these compounds observed to be 0.35 μB and 0.37 μB respectively. The magnetic moment per formula unit at 5 K, estimated from magnetization data, indicates a slight deviation from the Slater-Pauling relation. The Curie temperature was found to decrease with the Co substitution. Low temperature resistivity data in the temperature range of 18-100 K was observed to follow the relation ρ = ρ0 + A T2 + B T4.5. © 2009 Elsevier Ltd. All rights reserved.