The fabrication of aminotetrazole–palladium(II) complex immobilized on silica-encapsulated Fe3O4 magnetic nanoparticles is described with full characterization using XRD, TGA–DTG, EDS, TEM, FESEM, VSM and FTIR spectroscopy. This prepared core–shell entity has been explored as a highly efficient reusable nanocatalyst with superior stability and high catalytic activity in the reduction of hexavalent chromium [Cr(VI)], nitroarenes and azo dyes compared to other reported Pd-based nanocatalysts. The catalytic activity of the catalyst for the reduction of Cr(VI), 2,4-dinitrophenylhydrazine, 4-nitrophenol, methyl orange, Congo red, nigrosin and rhodamine B with sodium borohydride (NaBH4) aqueous solution or formic acid is evaluated by UV–Vis spectroscopy. The present study illustrates an unprecedented example of arylaminotetrazole grafted on magnetic nanoparticles as an excellent magnetically recoverable catalyst which can be recycled seven times without any meaningful changes in the reaction time.