The superconducting, magnetic and structural properties of intermetallic compounds V3−xFexSi and V3−xMnxSi have been investigated. The crystal structure is of the β‐W type up to about x=0.5 in both systems, with the lattice parameter decreasing with increasing x. The superconducting transition temperature, TS, and the upper critical field, Hc2, were determined from resistivity measurements. For x=0.015 in V3−xFexSi, Hc2 was enhanced over that oif V3Si. However, no such enhancement was found upon addition of Mn impurities to V3Si. Susceptibility measurements indicate a local moment on Fe in V3−xFexSi with μeff∠1.2 μB. No detectable moment was associated with Mn in V3−xMnxSi. These results indicate an antiferromagnetic coupling between Fe and conduction electron spins. On the Fe‐rich side (x=2.0 to 3.0), the crystal structure was of the cubic BiF3 type. In this region the Curie temperature decreased with increasing vanadium content.