The formation of W2C phases in the WC-Co coatings applied by APS is one of the biggest problems that occur in this type of coatings, because they are fragile and it is reported that they decrease the quality of the coating and its wear resistance, these phases are normally presented by the high temperatures of this technique which leads to a high decarburization of the WC-Co system. In this work the effect of the use of CO2 in the atmospheric plasma spraying technique was evaluated using x-ray diffraction and phase quantification by rietveld refinement method and it was found that the use of this gas has a positive effect on the reduction of free carbon and the decrease in the decarburization of the WC-Co system.