In this paper, we report the synthesis of a novel magnetically recoverable catalyst by immobilization of a copper (II)-5-phenyl-1H-tetrazole complex on the surface of Fe3O4@SiO2 nanoparticles [Fe3O4@SiO2-Tet-Cu(Il)]. The catalyst was fully characterized by using different techniques such as XRD, FE-SEM, EDS, TEM, FT-IR, VSM and TG-DTA. The [Fe3O4@SiO2-Tet-Cu(II)] was used for the reduction of 4-nitrophenol (4-NP), 2,4-dinitrophenylhydrazine (2,4-DNPH), methylene blue (MB) and Nigrosin (NS) in aqueous medium at room temperature by using NaBH4 as a reducing agent. Catalytic performance studies revealed that [Fe3O4@SiO2-Tet-Cu (II)] catalyst have excellent activity towards reduction reactions under mild conditions. The reaction process was monitored by using UV-Vis spectroscopy. Easy preparation, high catalytic activity, short time of reaction, and simple recovery from the reaction mixture are the specific properties of this efficient catalytic system. The catalyst can be easily recovered by using an external magnet and reused for at least five cycles without significant decrease in performance. These findings revealed that [Fe3O4@SiO2-Tet-Cu(II)] is a good catalyst and it can be used for different catalytic systems as a catalyst.