Polypropylene/polyamide 6 blends and their nanocomposites with layered silicates or talc were prepared in a melt-compounding process to explore their mechanical performance. The thermornechanical behavior, crystallization effects, rheology, and morphology of these materials were studied with a wide range of experimental techniques. In all cases, the inorganic filler was enriched in the polyamide phase and resulted in a phase coarsening of the polypropylene/polyamide nanocomposite in comparison with the nonfilled polypropylene/polyamide blend. The mechanical properties of these nanoblends were consequently only slightly better than those of the pure polymers with respect to the modulus, whereas the impact level was below that of the pure polymers, reflecting the heterogeneity of the nanoblend. Polymer-specific organic modification of the nanoclays did not result in a better phase distribution, which would be required for better overall performance. (c) 2006 Wiley Periodicals, Inc.