The organic-inorganic hybrid of hexa(aminophenyl)cyclotriphosphazene (CPA) was synthesized by reacting hexachlorocyclotriphosphazene with 4-acetamidophenol followed by hydrolysis. The resulting product CPA was then allowed to react with 2,2-bis(4-cyanatophenyl)propane (cyanate ester) in different ratios (5, 10, and 15%) to form six-membered oxygen-linked triazine ring with formation of highly cross-linked network structure. Thermal curing behavior was confirmed using Fourier transform infrared spectroscopy analysis and thermal properties were studied using thermogravimetric analysis and differential scanning calorimetry analyses. Dielectric constant and dielectric loss were measured using impedance analyzer. Data resulted from different studies indicate that these hybrid composites can be used for high-performance thermal applications in the place of conventional cyanate esters for better performance. © The Author(s) 2013.