Elephantopus scaber has been used in Brazil as a traditional remedy to cause diuresis, antipyresis and to eliminate bladder stones. In the current study, aqueous and hydroalcoholic extracts of whole plants were tested for acute toxicity, analgesic, antipyretic, antiinflammatory, cardiovascular, diuretic and constipating activities. Both extracts (0.3-6 g/kg i.p.) induced writhing, loss of muscle tone, ataxia, prostration and death in mice. No analgesic effects of these extracts were detected using mouse hot-plate and acetic acid-induced writhing tests. Both extracts failed to modify diuresis or carrageenan-induced rat paw edema. In contrast, given intraperitoneally, both reduced brewer's yeast-induced hyperthermia in rats, but when given orally did not affect it. Moreover, the aqueous extract decreased the intestinal transit time in mice while the hydroalcoholic extract increased it. Finally, these extracts, given intravenously, reduced blood pressure and heart rate in rats; these effects could be blocked by atropine but not by co-administration of pyrilamine and cimetidine.