Co-Cr-Mo (CCM) alloys, which are used in biomedical implants, are currently produced by additive manufacturing, for which accurate modeling of the process is required to attain the desired thermophysical properties of the melts. For the purpose of modeling, the density, surface tension, and viscosity of two CCM melts of distinct carbon content (0.05 and 0.25% by mass) were measured using an electrostatic levitation technique. The temperature dependence of both density and surface tension of the melts were assumed to be linear, whereas that for viscosity was assumed to have Arrhenius form, from which the activation energy corresponding to the viscous flow of each CCM melt was obtained. Using the Szyzkowski model along with our present and previous results, the influence of the partial pressure of oxygen on the surface tension of the two CCM melts was evaluated. No substantial difference in surface tension and viscosity between these melts was found.