Polyurethane closed cell (PUCC)/SiO2 nanocomposites have been prepared by using in situ polymerization approach. The third-order optical nonlinearities of PUCC/SiO2 nanocomposites, dissolved in DMF are characterized by Z-scan technique at the measurement wavelength of 532 nm. The nonlinear refractive (NLR) indices and nonlinear absorption (NLA) coefficients of samples were calculated from closed and open aperture Z-scan in the order of 10-8 with negative sign and 10-5 , respectively. The origin of optical nonlinearity in this case may be attributed due to the presence of two photon absorption (TPA) effect. The synthesized samples were examined by optical microscopy, SEM imaging and Raman spectroscopy. All the results related to NLO properties, suggest that PUCC/SiO2 may be a promising candidate for the application to optical limiting in the visible region.