In industrial applications and laboratory studies, it has been shown that the use of water spray may significantly reduce the amount of fume generated from the oxidation process of liquid high carbon ferromanganese alloy. However, in our recent study, it was shown that the oxidation rate of liquid silicon alloy increases with increasing water content in the atmosphere. Therefore, in this paper, the effect of moisture on the oxidation and fume formation of a liquid silicomanganese alloy was investigated. The fuming rate, fume characteristics, and experimental observations from wet air experiments on the silicomanganese melt were compared with those obtained from dry air experiments, and with the results of wet air experiments conducted on high carbon ferromanganese and silicon melts. In addition, the oxidation process of the silicomanganese and high carbon ferromanganese melts was modeled under the experimental conditions, using FactSage 8.1 thermochemical software, to better understand the equilibrium thermodynamic principles of the experimental results. In general, there was good agreement between the simulated and experimentally observed oxidation behavior of silicomanganese and high carbon ferromanganese melts under moist air conditions.