Presently, polymer-clay composites (PCC) have shown promising advancements in different properties of polymers due to presence of layered silicate structure and also extend its multi fold advanced applications. In the present work, vermiculite (VT) was organically modified by cetylpyridinium chloride (CPC). Thus obtained organo vermiculite (OVT) was used to prepare its composite film with polystyrene (PS-OVMT) with varying amounts of OVT by the solution blending and casting method on a glass substrate. The prepared films were characterized by scanning electron microscope (SEM), x-ray diffraction (XRD), infrared (FT-IR) spectroscopy and thermal analytical (TG-DTA) techniques. X-ray diffraction pattern of the composite shows peaks of VT and PS along with decrease in the intensity of the PS peaks present between 2Ө = 12.5˚ to 24.5˚. Decreases in the intensity of peaks suggest dispersion of clay within the polymer matrix and lowering of crystallinity. The dispersion of clay and interaction with PS is also evident from the FTIR and microscopic data. Further, hardness test (shore-D), TG-DTA and flammability(UL-94) results of the composite indicate the improvement in hardness, thermal stability and inhibition in burning behaviour of the PS due to the presence of OVT in the PS matrix. Copyright © 2017 VBRI Press.