A novel method for the synthesis of 5-substituted 1-H tetrazoles has been developed using one-pot tandem reactions of aryl halides with K₄[Fe(CN)₆] and sodium azide in the presence of cross-linked poly(4-vinylpyridine)-stabilized Pd(0) nanoparticles, [P₄-VP]-PdNPs. The catalyst was characterized using various techniques such as FT-IR and UV-vis spectroscopy, AAS, TEM, FESEM, EDX analysis, XRD and XPS. The results confirm a good dispersion of palladium nanoparticles on the polymer support. The catalyst is reusable many times without a significant loss in its activity.