Novel bifunctional fluorescent magneto polymeric nanoprobes (FMPNs) were synthesized to provide simultaneous diagnostic information via magnetic resonance imaging (MRI) and optical imaging. FMPNs consist of ultra-sensitive magnetic nanocrystals that function as MR probes combined with Nile Red, which functions as a fluorescent probe. FMPNs were encapsulated by a nano-emulsion method in polyvinyl alcohol (PVA, 87-89% hydrolyzed) through a matrix of polymethyl methacrylate (PMMA). FMPNs exhibited excellent colloidal stability and monodispersity. The production of MR and optical images demonstrated that FMPNs have potential as dual-mode imaging agents. Crown Copyright (C) 2009 Published by Elsevier Inc. All rights reserved.