The in-flight nitridation of MoSi2 powders has been carried out by using an Ar-N-2 induction plasma, with and without tail gas quenching. The effects of plate power level, reactor pressure and plasma gas composition on the nitridation of MoSi2 powder particles were investigated. The average nitrogen content measured in the in-flight plasma treated MoSi2 powders was approximately 2.8 wt.%. The distribution of nitrogen inside the nitrided MoSi2 powder particles was determined by scanning the cross-section of mounted plasma nitrided MoSi2 powder particles by means of Auger electron spectroscopy (AES). The nitridation mechanism for the MoSi2 powders in the induction plasma process is briefly discussed.