Abstract The oils and extracts of the fruit peels of pomelo (Citrus maxima Merr. cultivar 'khao-yai') were obtained by cold-pressing (CP), vacuum steam distillation (VSD) and supercritical carbon dioxide extraction (SC-CO2) and the extract of the flowers was obtained by SC-CO2. The composition of the oils and extracts of the peel and flower were determined by GC and GC/MS. Fifty, 53 and 60 components of the oils and extract from peels by CP, VD and SC-CO2 were identified, respectively. Their main components were limonene (93.4â95.4%). Fifty-one components of the flower extract were identified and the main component was also limonene (86.2â86.8%). The oils and extract of pomelo showed fairly good activity against Staphylococcus aureus and Candida albicans. Key Word Index: Citrus maxima Citrus grandis Rutaceaeessential oil compositionlimoneneantimicrobial activity