A high-strength in situ composite of MoSi2/SiC was synthesized using a solid state displacement reaction between Mo2C and Si by blending Mo2C and Si powders and vacuum hotpressing the powders at 1350°C for 2 h followed by 1 h at 1700°C. The resulting microstructure consisted of 1-μm diameter β-SiC particles (30 vol%) uniformly dispersed in a fine grained MoSi2 matrix. Transmission electron microscopy was used to study the fine-scale morphology and phase distribution of the composite. Evidence for a small amount of grain boundary glass phase was observed using diffuse dark field imaging. The β-SiC particles were distributed mainly on grain boundaries and triple points within the MoSi2 matrix. These findings were used to rationalize the observed mechanical property behavior.