In the active component testing citronellal, the major component in makrut leaf oil, was found to be more active than the whole makrut leaf oil against A. baumannii, Streptococcus spp., MSSA, and MRSA (Table 2). Likewise, α-terpineol, followed by terpinene-4-ol, were more active against A. bau- mannii, Streptococcus spp., and H. influenzae ATCC 49766 than makrut lime oil (Table 3). However, limonene, the most predominate component of makrut oil, had a much less antibacterial activity.