ABSTRACT. The investigation of the volatile compounds of essential oils of propolis from two geographic origins of Ethiopia (Haramaya and Assela) was made by GC-MS. A total of 62 components of the oil were identified from both samples. The identified constituents of the oils may be divided into seven different groups: oxygenated monoterpenes (29.81% Haramaya, 9.45% Asella), sesquiterpenes (15.20% Haramaya, 19.05% Assela), oxygenated sesquiterpenes (11.86% Haramaya, 18.56% Assela), aromatic (14.93% Haramaya, 4.25% Assela), oxygenated aromatic (17.59% Haramaya, 4.58% Assela), aliphatic (5.06% Haramaya, 7.62% Assela) and oxygenated aliphatic (7.84% Haramaya, 25.17% Asella). The major volatile compounds of Haramaya propolis consist of calamenene (13.82%), 4-terpineol (8.57%), epi-bicyclosesquiphellandrene (8.37%), 4-(2-acetyl-5,5-dimethylcyclopent-2-enylidene)butan-2-one (7.83%) and 3-isopropyl-6-methyl-2-oxo-1-(3-oxobutyl)-cyclohexanecarbaldehyde (5.90%). Whereas the most abundant constituents of Assela propolis were 5,6,7,8-tetramethylbicyclo[4,1,0]hept-4-en-3-one (15.01%), acoradien (13.77%), epicedrol (6.80%) and (6E,6E)-3,7,11,15-tetramethyl-1,6,10,14-hexadecatetraen-3-ol (6.14%). Ten compounds which were found in both samples of propolis were trans-pinocarveol,
