The components of the volatile oil from wild mushroom (Lactarius hatsudake), used in Japanese traditional food, were analysed and quantified for the first time by capillary GC and GC–MS. Seventy‐six components were separated from the oil and of these 71 components were identified. The main components of the oil were oxidized sesquiterpenes [cis‐isolongifolanone (624.9 μg/100 g), α‐cedrene epoxide (578.7 μg/100 g), humulene epoxide III (453.9 μg/100 g), clovane (425.4 μg/100 g)], aliphatic acids [linoleic acid (585.9 μg/100 g) and palmitoleic acid (333.3 μg/100 g)]. Odour evaluation of the volatile oil from L. hatsudake was also carried out using GC–MS/olfactometry (GC–MS/O) and aroma extract dilution analysis (AEDA), from which it was found that hexanal, 4‐dehydroviridiflorol, myliol and phenylacetaldehyde seem to contribute to the green, spicy and sweet odour of L. hatsudake. Copyright © 2010 John Wiley & Sons, Ltd.