The effect of nanoclay as compatibilization agent and thermal stabillizer of Polycarbonate/styreneacrylonitrile blend was investigated. Different PC / SAN compositions with and without presence of clay were prepared by extruding and then annealed to investigate the morphological stability. This study also evaluated the influence of different organic modifiers, by using cloisite® 20A and 30B clays, and acrylonitrile contents in the morphology development. The SEM analysis indicates that the clay acts effectively reducing the domain size of SAN even without fully exfoliation. It was also observed that nano-clays with nonpolar organic modifiers were preferably in SAN domains. On the other hand, blends containing nano-clays with polar modifier showed that clay particles migrated to interface resulting in domain reduction and even better morphological stability. The acrylonitrile content had a minor role on the development of the morphology of the blends