Essential oils prepared by hydrodistillation of leaves (L), rhizomes (R), and stems (S) of Alpinia speciosu (J.C.Wendl.) K. Schum. [=Languas speciosa (J.C.Wendl.) Merrill], Family Zingiberaceae, were analysed by capillary gas chromatography coupled to mass spectrometry (CGC-MS). Individual components of the oil of each organ were identified by their Kovats indices and their mass spectra which were compared with published material or with data of reference compounds. Quantitative determination was carried out based on peak area integration. The study revealed that the oxygenated compounds constitute 41.7%, 52.1% and 42.8% of the oil in L, R and S, respectively. They are composed mainly of terpinen-4-ol (17.3%, 20.2% and 16.0%) and 1,8-cineole (14.4%, 15.9% and 11.5%) in L, R and S, respectively. The hydrocarbons constitute 52.2% (L), 40.9% (R) and 44.3% (S) of the oil, and comprise mainly sabinene 10.1% (L), 9.8% (R) and 7.5% (S) and gamma-terpinene 11.1% (L), 9.3% (R) and 8.2% (S). The essential oils of the three organs exhibited significant antimicrobial activity against certain Gram-positive and Gram-negative bacteria as well as Candida albicans.