A study is reported of the formation of ultrafine SiC powder through the reaction of elemental silicon and CH4 in an induction plasma. The reaction route used involved in the first place the vaporization of a fine elemental silicon powder axially injected into the center of the discharge followed by the carburization reaction through the coinjection of CH4. The powder obtained was composed of a mixture of alpha- and beta-SiC with varying amounts of free carbon and free silicon. The particle size distribution was typically in the range of 40-60 nm with a corresponding specific surface area of 30-50 m(2)/g. A parametric study showed that the quality of the powder obtained varied with the plasma plate power and the position of the injection probe. The plasma gas composition employed was found to influence the proportions of alpha- and beta-SiC in the synthesized SiC powder. With an Ar/N-2 mixture as the plasma gas, the ratio of the alpha to beta phases was less than 1.0, whereas the ratio was greater than 1.5 when using a mixture of Ar/H-2 as plasma gas. The Si powder feed rate and the input C/Si molar ratio in the injected reactants significantly affected both the formation of the SiC and the free Si and free C content in the synthesized powder. Lining the cylindrical reactor wall with graphite resulted in improved conversion of Si to SiC. The weight fraction of the powder collected at different sections of the reactor system varied with the reactor operating conditions. The experimental results support the view that the formation mechanism for ultrafine SiC is dominated by the reaction of Si vapor with the thermal decomposition products of CH4.