The distillation and subsequent extraction of the distillate obtained from the fresh peels of the fruits of Citrus macroptera var. annamensis afforded 120 mg of oil (yield 0.12 %). Analyses both by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) of the sample resulted in the identification of 25 terpenoids, predominantly monoterpene hydrocarbons, accounting for 97.0 % of the total oil, and limonene (73.5 %) as the major component. While the oil did not exhibit any in vitro free-radical-scavenging (DPPH), it showed considerable antibacterial activity against Bacillus cereus, B. subtilis, Escherichia coli and Staphylococcus aureus with the MIC values ranging from 1.25 to 5.0 mg/mL.