The brown-rot fungus Gloeophyllum odoratum was collected from spruce stumps in southern Finland. The volatiles in the fruiting body and fungal cultures grown in malt extract and liquid medium were investigated. Chitin, chitosan and D-(+)-glucosamine at a concentration of 450 mgl-1 medium were used as elicitors. Chitosan completely inhibited growth in the solid medium. The main volatile(s) according to GC and GC-MS analysis were either linalool, citronellol, geraniol and methyl p-methoxyphenylacetate or drimenol depending on the culture type and elicitor. The composition of volatiles in the natural fungus differed slightly from that of the cultivated fungus since the major compound was methyl p-methoxyphenylacetate. The volatile oils were toxic to larvae of the brine shrimp, Artemia salina, indicating that they may possess insecticidal and cytotoxic activity.