Two female specimens of an undescribed species of stylocellid harvestman (Opiliones, Stylocellidae) from Sulawesi were extracted in methanol, and compounds in the product were identified by means of gas chromatography-mass spectrometry. Nineteen significant peaks were found, 12 of which were identified, indicating the presence of naphthoquinone, 2-tridecanone, 2-tetradecanone, 2-pentadecanone, 6-methyl-1,4-naphthoquinone, 6-methyl-1,4-naphthalenediol, and at least four unsaturated ketones. The spectrum differed both qualitatively and quantitatively from previously published data on Siro exilis Hoffman 1963 and Cyphophthalmus duricorius Joseph 1868 (Sironidae).