Fe3O4/ZnS nanocomposite (NC) having magnetic and fluorescent properties are synthesized via a chemical route. XRD results confirm that the NC does not have undesired phases and the constituents have particle size in the nanometer regime. PL emission spectra have shown strong near band edge emission (NBE) in the UV region as well as defect related bands in the visible region. A blue shift of the NBE emission has been observed for the NC with respect to that of the pristine ZnS. Magnetization measurements of the NC and pristine Fe3O4 show typical hysteresis loops showing ferrimagnetic behavior. The irreversibility observed in the ZFC-FC measurements shows presence of a relaxing phase in the NC whereas the hump seen in the ZFC curve indicates the Verwey transition of magnetite.