The bark and wood of an endemic oak species in Turkey, Q. vulcanica, were investigated with regard to main components, phenolics as well as extractives. About 66 % of extract free wood consists of polysaccharides, i.e. cellulose and polyoses. Heartwood was found to be rich in ellagitannins, while in bark proanthocyanidins occurred in larger amounts. Extractives soluble in cyclohexane were divided into saponifiables and neutrals. Among saponifiables saturated acids made up the majority, while sterols and nonsteroidal triterpenes were the predominating compounds of the neutral fraction.