Abstract Composites of isotactic polystyrene with different loading of titanium dioxide were prepared by melt mixing in a Brabender Plasticorder at a rotor speed of 60 rpm at 180 °C. Mechanical properties of the composites were measured by various techniques and most of the properties were found to be increasing with filler loading. Tapping mode atomic force microscopy was used to study the surface characteristics of the composites. Various AFM analytical parameters like power spectral density, roughness analysis and section analysis were measured. The mechanical properties of the composites were correlated with analytical data obtained from the AFM studies. The focused ion beam technique was also used to characterize the dispersion of the filler in the polymer matrix.