In recent years, the potential of oral care in preventing aspiration pneumonia has been recognized. Consuming drinks is thought to be an easy and effective method of oral care, and the antibacterial activities of various drinks have been examined. However, the side effects associated with, for example, caffeine as an ingredient in tea (e.g. sleep disorders) need to be taken into consideration. As yet, a safe caffeine-free tea to be taken orally to prevent aspiration pneumonia has not been reported. Thus, in the present study we evaluated the antibacterial effects of hot water extracts of four teas, namely Hypericum Erectum, Crataegus cuneata, Rosa canina, and Matricaria rectita, thought to be caffeine-free. The effects of the extracts against 19 bacteria and 1 fungus were investigated by the dilution plate technique. In addition, the components of the teas were analyzed by HPLC analysis. The strongest antibacterial activity was observed for the hot water extract of H. erectum, which exhibited significant activity against oral bacteria, including Streptococcus oralis. However, the H. erectum extract did not kill microbiota, such as Escherichia coli and Lactobacillus casei. Neither hypericin nor caffeine, both of which have notable side effects, were detected in the H. erectum extract following HPLC analysis. These results suggest that H. erectum tea may be a good candidate for simple, safe oral care to prevent aspiration pneumonia in the elderly.