Two acid dyes having excellent antimicrobial activity were synthesized by using silver sulfadiazine, a well-known antibiotic, and 8-amino-1-naphthol-3,6-disulfonic acid (H-acid). The diazonium salt of silver sulfadiazine (S1) and the acetylated H-acid (H1) were prepared first, and then an antimicrobial red acid dye (Acid-Red) was synthesized via a coupling reaction of S1 and H1. An antimicrobial blue acid dye (Acid-Blue) was also synthesized by the successive coupling reactions of H-acid with the diazonium salt of aniline-2,5-disulfonic acid (B1) and the diazonium salt of sliver sulfadiazine (S1). Two colorless antimicrobial additives for disperse dyeing, Disperse-ES and Disperse-AS, were also synthesized by reacting silver sulfadiazine with diethyl sulfate and acetic anhydride, respectively. The synthesized antimicrobial dyes and additives were characterized by Fourier transform infrared (FT-IR), UV-vis, and energy dispersive X-ray (EDX) analyses. Although the nylon fabric dyed with either Acid-Red or Acid-Blue showed poor light fastness, it had good washing and crocking fastness. The nylon fabrics dyed with Acid-Red and Acid-Blue and polyethylene terephthalate (PET) fabrics treated with Disperse-ES or Disperse-AS showed excellent antimicrobial activities after 10 repeated launderings.