We report on a novel catalytic system based on electrospun polymer nanofibers, which were modified with a metal containing polyhedral oligomeric silsesquioxanes (M-POSS). In particular, a titanium based POSS, characterized by an amino group as reactive side, was contacted with poly(styrene-co-maleic anhydride) (PSMA) nanofibers, which were dispersed in a solvent capable of solubilizing the above metal silsesquioxane. FTIR Measurements evidenced the occurrence of the reaction between the MA group of PSMA and the amino group of POSS molecule. The catalytic activity of the PSMA/Ti-POSS-NH2 system was proved in the degradation of sulforhodamine B under UV light. The presence of metal center, directly attached to the nanofiber surface, renders the system catalytically active.