Chitosan (CS) coated magnetic-fluorescent nanoparticles (CS-Fe3O4@ZnS:Mn) were synthesized in aqueous media under ambient pressure and characterized by X-ray diffraction, UV-vis absorption, fluorescence emission, transmission electron microscope and energy dispersion spectrum. The effects of experimental conditions on the fluorescence properties of CS-Fe3O4@ZnS:Mn were studied. It was found that the chitosan coating on the surface of Fe3O4 could effectively suppress the interaction between Fe3O4 and ZnS:Mn, as well as providing appropriate functional groups for the synthesis and modification of ZnS:Mn semiconductor nanocrystals. The obtained multifunctional nanoparticles are promising candidates for applications in simultaneous biolabeling, imaging, cell sorting and separation. (C) 2012 Elsevier B.V. All rights reserved.