A novel catalyst was prepared by the immobilization of salen molybdenum complex on dendrimer functionalized magnetic nanoparticles. Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), N-2 adsorption-desorption isotherms, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometry (VSM), inductively couple plasma atomic emission spectroscopy (ICPAES), and elemental analysis were used to characterize the catalyst. The synthesized catalyst was highly active and selective for the epoxidation of various olefins in the presence of tert-butyl hydroperoxide (TBHP) as oxidant. Notably, the catalyst could be separated easily by applying an external magnet and recycled up to six cycles without significant decrease in catalytic activity and selectivity.