We investigated the natural antimicrobial activities of Capsella bursa-pastoris water, methanol, and ethanol extracts. Antimicrobial activities of these extracts and sodium benzoate on Bacillus cereus, Staphylococcus aureus, and Escherichia coli were compared. The inhibition zone diameters of the methanol and ethanol extracts of Capsella bursa-pastoris were 13-20 mm and 12-20 mm, respectively, which were larger than those of sodium benzoate (11-15 mm). The minimum inhibitory concentrations of Capsella bursa-pastoris methanol and ethanol extracts were 12.5-20 mg/mL. These results indicate that Capsella bursa-pastoris methanol and ethanol extracts can be used as natural antimicrobial agents.