Nanocomposites based on a SBS triblock copolymer and organomodified layered silicates were prepared by solution casting followed by melt shearing. The dispersion of the nanofiller in the polymer matrix and its influence on the mechanical behavior of the composites were determined by means of different microscopic techniques, tensile testing, dynamic mechanical analysis, and microindentation hardness measurements. It was found that the procedure used for the composite preparation was suitable to obtain optimum dispersion of the nanofiller. A significant improvement in the Young's modulus was observed at a filler content of 10 wt% while the other tensile properties remained unchanged. As demonstrated by microhardness measurements, the mechanical reinforcement was verified by a parallel increase in hardness with increasing filler,content.