A series of new 1,2,4‐triazole‐3‐thiones were synthesized by calm, benign, no risk, eco‐friendly, and energy efficient sequential reaction methodology like grinding and ultrasonic (US). In addition, 1,2,4‐triazoles were prepared under conventional method and comparative study was done. The synthesized 1,2,4‐triazoles were complexed with Ni(II) to produce nanoparticles complexes (NPC's) with average particle size vary from 55 to 100 nm (using scanning electron microscope technique) with good yields via both US and conventional techniques. X‐ray diffraction technique and spectra analysis techniques were used to confirm the square planer geometry of the synthesized NPC's. Antimicrobial activity of the prepared 1,2,4‐triazoles and their nickel complexes were studied which evaluated a high activity with complexes instead their triazoles.