Abstract: Recently, the design and applications of new methods in organic synthesis based on multicomponent reaction (MCRs) is attracted academic and industrial research groups. On the other hand, imidazoles are a very interesting class of heterocyclic compounds, because they have many pharmacological properties such as angiotensin inhibitors, anti-inflammatory, glucagon antagonist, antiviral, antimicrobial, fungicidal and etc. Progress in nanoscience and nanotechnology have attracted researchers toward the synthesis of functional magnetic nanoparticles (MNPs), which is one of the most active research areas in advanced materials. MNPs that have unique magnetic properties and other functionalities have enabled a wide spectrum of applications. Magnetic nanocatalysts can easily be separated and recycled from the products by an external magnet. Moreover, their catalytic performance is improved, for the available surface area of the nonoporous MNPs is external and the internal diffusion is practically avoided.In continuation of our interest in the application of new catalysts in organic synthesis via MCRs, herein, an efficient and highly selective synthesis of substituted imidazoles has been developed by the condensation of benzil or benzoin with various substituted aldehydes and ammonium acetate using urea-functionalized Fe3O4@SiO2 magnetic nanoparticles as a catalyst under mild reaction conditions and excellent yields.