The synthesis, mesomorphic character, and effect of spacers in ferrocene-containing main-chain liquid-crystalline polymers are reported in this article. Two different monomers containing ferrocene and phenyl/biphenyl phosphate groups possessing even numbers of spacers from 2 to 10 were prepared and polymerized by polycondensation at room temperature. All the polymers gave birefringent melt except one. The identification of the mesophase was transparent with an increase in spacers. The effect of substitution in the side chain with regard to bulkiness and spacers were studied with thermogravimetric analysis and differential scanning calorimetry. The results reveal that the thermal stability of the polymers increased with the increasing bulkiness of the side chain and decreased with increasing spacer length. The incorporation of the phosphorous moiety also had a considerable effect on the glass-transition temperature. Char yield of the polymer decreased with increasing methylene chain length, and it did not vary much with the size of the pendent groups.