Astraeus spp. is consumed in several regions of Southeast Asia. C(8) compounds, including 1-octen-3-ol, are the main volatile compounds in fresh Astraeus spp. Other compounds typical of edible mushrooms, such as terpenoids and sulfur-containing compounds, were not detected in fresh Astraeus spp. The amounts of fatty acids, including linoleic acid, substantially decreased after homogenization of fresh Astraeus spp. This high metabolic activity possibly correlates with formation of the C(8) volatiles. Heating the mushrooms produced cyclohexene compounds, 2-n-pentyl-furan, furanyl compounds, and benzaldehyde.