Group II–VI cadmium sulfide nanoparticles (CdS NPs), a potential alternative to antibiotics, were synthesized using cadmium acetate [Cd(Ac)2] as a precursor, sodium sulfate as a reducing agent, and starch as a capping agent through chemical precipitation techniques. The CdS NPs were characterized using different characterizing techniques; X-ray diffraction and selected area electron diffraction patterns verify that the nanoparticles had cubic zinc blende structure with average dimension size of 2.43 nm. Scanning electron mictroscope and transmission electron microscope images illustrated that the particles were uniformly distributed in cluster form, and FTIR and EDX confirmed the synthesized nanoparticles were pure. The CdS NPs show relevant antimicrobial sensitivity against Gram-positive and Gram-negative bacterial strains and the zone of inhibition increases with the increase in the concentration of nanoparticles. In comparison to Gram-positive and Gram-negative bacteria, the synthesized nanoparticles were reported to be more effective toward Staphylococcus aureus, Gram-positive bacteria.