Inorganic polymers are attractive precursors for high‐performance ceramics. A new method of producing the polymers via thermal polycondensation of volatile molecular precursors is presented which does not involve the use of catalysts and therefore avoids contamination of the polymers with the catalysts or with byproducts of the catalytic reaction. The example presented is the polycondensation of tetrakis(methylamino)silane, which is a readily available precursor for Si3N4/SiC ceramics.