In this work, the green synthesis of silver-silver chloride nanoparticles (Ag@AgClNPs) has been used the plant leaf extract of Chromolaena odorata (C. odorata) as a reducing and capping agent. The effects of parameters on the formation of Ag@AgCl nanoparticles (Ag@AgClNPs such as the ratio of C. odorata raw material/water, the extraction temperature, the extraction duration, and the volume ratios of AgNO3 solution and C. odorata extract have been studied. The obtained Ag@AgClNPs sample was characterized by ultraviolet visible spectroscopy, X-ray diffraction spectroscopy, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, and transmission electron microscopy. UV–visible absorption studies revealed surface plasmon resonance peak around 420‒450 nm, confirming the presence of Ag@AgClNPs. The average particle size was approximately 15.2 nm. The antibacterial activity of Ag@AgClNPs was carried out by the agar well diffusion method and the determination of the minimum inhibitory concentration that showed high toxicity against the gram-negative bacteria (Escherichia coli, Salmonella typhi, and Pseudomonas aeruginosa) and the gram-positive bacteria (Bacillus cereus and Staphylococcus aureus).