In this research, poly (4-vinyl pyridine)-supported nickel oxide nanoparticles (P4VP-NiO nanocatalyst) as an efficient recyclable catalyst have been prepared and used for the regioselective synthesis of triazole derivatives. The nanocatalyst we characterized by Fourier-transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), x-ray diffraction (XRD), thermogravimetric analysis (TGA), inductively coupled plasma (ICP), and brunauer-emmett-teller (BET) surface area analysis. The most important advantages of using poly (4-vinylpyridine)-nickel oxide nanocatalysts in these reactions are the short reaction time, cost-effectiveness, easy recycling of the catalyst, and high yield of the product. Also, the antimicrobial properties of the new triazole derivatives have been studied.