Xylaria, belonging to the Ascomycotina, is known to produce diverse classes of bioactive substances. In an effort to identify the chemical constituents of the fruiting bodies of Xylaria polymorpha, linoleic acid (1), linoleic acid methyl ester (2), ergosterol (3), 4-acetyl-3,4-dihydro-6,8-dihydroxy-3-methoxy-5-methyl-1H-2-benzopyran-1-one (4), and 4-hydroxyscytalone (5) were isolated from its methanolic extract. Their structures were assigned on the basis of various spectroscopic studies.