Mo-Si-B alloys provide a significantly higher creep resistance at temperatures above 1100 °C compared with Nickel-based superalloys. However, the high density of this alloy is a drawback when used as a turbine blade material. One approach to reduce the density of Mo-Si-B alloys, without decreasing the high temperature creep resistance too much, is alloying with vanadium. With this procedure a density reduction from 9.60 g/cm³ in Mo-9Si-8B to 7.73 g/cm³ in Mo-40V-9Si-8B can be achieved. Generally, in Mo-ZV-9Si-8B alloys (Z = 10, 20, 30, 40 at.%), phases like VxMo5–xSiB2 (T2 crystal structure), VxMo3−xSi (A15) and VxMo1−x (B2) are present and interestingly, the following behavior can be observed after alloying with V: Rietveld refinement revealed that at least in the Mo-40V-9Si-8B alloy vanadium prefers the 4c Wyckoff position in T2-V3Mo2SiB2. The present work will explain the reason of this observation using first principles density functional theory (DFT) calculations and also demonstrate the influence of V and Mo occupations in the T2-VxMo5–xSiB2 phases on the elastic properties like bulk modulus, shear modulus, Young’s modulus and Vickers hardness with the help of DFT.