An innovative, faster and nonconventional processing technique is demonstrated for preparing silicon carbide-based ceramics derived from polymer precursor. The technique is based on microwave-induced pyrolysis of an actively seeded, high-purity preceramic polymer that leads to rapid fabrication of silicon carbide components. It is successfully demonstrated that it is feasible to carry out microwave-induced pyrolysis by seeding the polymer precursor with very low volume fractions of micrometer and nanometer-sized metal and dielectric fillers. This process allows for rapid, net-shape, and potentially lowcost fabrication of silicon carbide-based materials. Mechanical properties and microstructure of the silicon carbide-based composites fabricated using this process are characterized.