The temperature dependence of the electrical resistivity of four CoGa alloys with a partial substitution of a 3d transition metal for Ga is reported. Both the magnitude of the measured resistivities ( approximately 200 mu Omega cm) and their variation with temperature are observed to be very similar to those of certain metallic glasses, with alpha ( identical to (1/ rho )( delta rho / delta T)) being small but negative for all four alloys. The results are found to be well explained by the inclusion of the temperature dependent Debye-Waller factor in the standard expression for the resistivity, this being the first time this factor has been shown to be of importance in a crystalline metallic system.