Herbal mate tea, known locally as 'chimarrao', is a stimulating beverage traditionally consumed by the Gauchos of South America. Infusions were prepared according to the method used by the Gauchos, and caffeine, chlorogenic acids and caffeic acid were determined in unhydrolysed and hydrolysed samples. An intake of 260 mg of caffeine, 240 mg of chlorogenic acids and 170 mg of caffeic acid was estimated, exceeding by far the intake recorded in the literature for other beverages containing these compounds. The factors influencing the concentrations of these compounds in the infusions indicate that higher amounts could be ingested. (C) 1997 Elsevier Science Ltd.6016771