The novel antimicrobial composition is disclosed including from about 60 to 95% of a lipophilic polar solvent such as propylene glycol, ethylene glycol, or isopropanol and from about 0.5 to 5% of a mixture of C.sub.8 to C.sub.14 fatty acids. Other constituents of the present invention may include water, an alcohol (such as ethanol or propanol) or a mixture thereof. Also disclosed is a novel method of killing harmful microbes on the udder of a milk-producing animal using the above-mentioned composition.