The study describes a simple and novel method for the synthesis of silver sulfide nanoparticles (Ag2S NPs). The synthesized NPs were characterized by SEM (scanning electron microscope), XRD (X-ray diffraction), particle size analyzer, zeta sizer and EDX (Energy dispersive X-ray). The Ag2S NPs were spherical in shape with an effective diameter size of 30 nm. The synthesized particles possess photocatalytic activity under visible light and exhibited excellent antimicrobial effect. The photocatalytic property of Ag2S NPs was also evaluated by the degradation of methylene blue dye under visible light. NPs degraded 87% of methylene blue with in 1h at pH 8. The NPs of 0.1 μg/mL showed a growth inhibition of more than 75% against S. aureus (ATCC 25923), E. coli (ATCC 13534), and E. coli (ATCC 25922).