Rubber nanocomposites based on hot styrene-butadiene rubber (SBR) and organophilic layered silicate were prepared via mechanical mixing followed by compression molding. Varying amount of organically modified nanosilicate, 2.5, 5, 10, and 15 parts per hundred of rubber (phr), was added to the SBR matrix to examine the influence of nanosilicate on morphology and structure–property relationships. The morphology of nanocomposites was studied by X-ray diffraction and transmission electron microscopy which reveal that the nanocomposite contained a good dispersion of intercalated/exfoliated layers through the matrix. The interaction between SBR matrix and nanofiller was studied by infrared spectroscopy. No clear evidence for the formation of new components in the rubber was found but infrared spectroscopy denoted evidence for exfoliation. The reinforcing effect of the nanosilicate was determined by mechanical testing and dynamomechanical analysis. The results indicate that the tensile properties and the storage modulus increased with increasing nanofiller loading. This suggests a strong rubber–nanosilicate interaction which is attributed to the exfoliated/intercalated structure. Thermogravimetric analysis revealed that incorporation of organoclay enhances the thermal stability of the nanocomposites. The best thermal stability was observed for nanocomposites containing 5 phr nanosilicate.