The essential oil of six Brazilian Hypericum species (Family Guttiferae) has been obtained by hydrodistillation: H. caprifoliatum Cham. & Schlecht. (0.2%), H. carinatum Griseb. (0.2%), H. connatum Lam. (0.1%), H. myrianthum Cham. & Schlecht. (0.5%), H. polyanthemum Klotzsch ex Reichardt. (0.2%) and H. ternum A. St. Hil. (0.1%). The composition of the oils was determined by GC and GC-MS and 84 compounds in total have been characterized. The principal constituents of each oil are: nonane (56%) in H. caprifoliatum, undecane (21%) in H. myrianthum, beta-caryophyllene (21%) in H. carinatum, caryophyllene oxide (40%) in H. connatum, beta-caryophyllene (12%) in H. ternum and the benzopyran HIP1 (6-isobutyryl-5,7-dimethoxy-2,2-dimethyl-benzopyran) (27%) in H. polyanthemum. Copyright (c) 2005 John Wiley & Sons, Ltd.