In situ solid state polymerization method was performed with mixtures of polyoxometalate (POM) and N-vinylcarbazole (NVC) in desired weight ratios for the synthesis of nanocomposites. The yield of the PNVC–H 4 SiW 12 O 40 nanocomposite increased with increasing amount of H 4 SiW 12 O 40 as well as with [H 4 SiW 12 O 40 ]/[PNVC] loadings. The formation of PNVC in the system was endorsed by FTIR, UV–vis, and 1 H 1 NMR spectroscopic analyses. HRTEM studies revealed that the PNVC–H 4 SiW 12 O 40 nanoparticles have an average grain size of 62.13nm and that the H 4 SiW 12 O 40 nanoparticles are fairly well-dispersed in the composite matrix. SEM analysis shows the presence of agglomerates of nano particles embedded in the matrix. AC conductivity (σ ac )–frequency variation was constant for PNVC but showed an increasing trend with higher H 4 SiW 12 O 40 :PNVC weight ratios in the composite.