Achyrocline satureioides (Lam.) DC. inflorescences have been used as remedies in folk medicine for the treatment of a variety of human ailments, particularly those of the gastrointestinal tract. Different extracts of inflorescences have been tested for anti-inflammatory, analgesic, antispasmodic, constipating and sedative activities. The aqueous extracts (maceration and decoction) and ethanolic macerate exhibited an inhibition of the carrageenan-induced rat paw oedema at a dose range of 75-500 mg kg-1 i.p., and also showed analgesic effect with the acetic acid-induced writhing test in mice. The gastrointestinal propulsion of a charcoal suspension was not affected significantly by any extract, at a dose of 200 mg kg-1 p.o., in mice. The aqueous decoction increased pentobarbital-induced sleeping time, at doses of 200 and 500 mg kg-1 i.p. and p.o., in mice. The ethanolic macerate inhibited contractions induced by acetylcholine, histamine, noradrenaline and barium chloride in four different smooth muscle tissues. The antispasmodic and anti-inflammatory activities were reproduced with quercetin, luteolin and quercetin 3-methyl ether, flavonoids that have been isolated from this plant. A partial evaluation of the toxicity of the extracts was also performed. The pharmacological effects assayed are discussed in relation to the chemical constituents of this plant and its popular use in gastrointestinal disturbances, and inflammatory conditions could be related to the presence of the flavonoids.