The green synthesis of Ag/AgCl nanocomposite using the durian shell extract was carried out under the sunlight illumination at room temperature, showing the face-centered cubic crystalline structures of both Ag and AgCl with nanosizes in the range of 15–25 nm. The high negative potential value of the Ag/AgCl solution (–21.1 mV) established the high dispersion of Ag/AgCl, long-term stability, and good colloidal nature. The antibacterial activity of Ag/AgCl nanocomposite against methicillin-resistant Staphylococcus aureus (MRSA) bacteria was highly appreciated with average inhibition zone diameter of 12.0 mm, minimum inhibitory concentration of 8.27 mg/L, and minimum bactericidal concentration of 66.1 mg/L. The present work designed a cost-effective, convenient, eco-friendly protocol to synthesize Ag/AgCl nanocomposite and its efficient antibacterial activity against MRSA was evidenced as well.