Antimicrobial bar compositions can include, for example, from about 0.1% to about 35%, by weight of the antimicrobial bar composition, of water; from about 45% to about 99%, by weight of the antimicrobial bar composition, of soap; and from about 0.01% to about 5%, by weight of the antimicrobial bar composition, of platelet zinc pyrithione (“platelet ZPT”). The platelet ZPT includes a median particle diameter of about 2 microns to about 3 microns, a mean particle diameter of about 3 microns to about 4 microns, and a thickness of about 0.6 microns to about 15 microns.